diff --git a/apps/as/src/entities/esntl/api/esntl-service.ts b/apps/as/src/entities/esntl/api/esntl-service.ts
new file mode 100644
index 000000000..a8e60bc57
--- /dev/null
+++ b/apps/as/src/entities/esntl/api/esntl-service.ts
@@ -0,0 +1,22 @@
+import { client } from "@/shared/api";
+import { ENDPOINT } from "@/shared/config";
+
+import type {
+  EsntlAtchFileMngSearchParams,
+  EsntlAtchFileMngService,
+  EsntlAtchFileMngTreeResponseDto,
+} from "../model/esntl-interface";
+
+async function findTree(
+  params: EsntlAtchFileMngSearchParams,
+): Promise<EsntlAtchFileMngTreeResponseDto[]> {
+  const response = await client.get<EsntlAtchFileMngTreeResponseDto[]>(
+    `${ENDPOINT.AS_COMMON_SERVICE.ESNTL_ATCH_FILE}/list/tree`,
+    { params },
+  );
+  return response.data;
+}
+
+export const esntlAtchFileMngService = {
+  findTree,
+} satisfies EsntlAtchFileMngService;
diff --git a/apps/as/src/entities/esntl/index.ts b/apps/as/src/entities/esntl/index.ts
new file mode 100644
index 000000000..dfe42c24b
--- /dev/null
+++ b/apps/as/src/entities/esntl/index.ts
@@ -0,0 +1,6 @@
+export type {
+  EsntlAtchFileMngSearchParams,
+  EsntlAtchFileMngService,
+  EsntlAtchFileMngTreeResponseDto,
+} from "./model/esntl-interface";
+export { esntlAtchFileMngService } from "./api/esntl-service";
diff --git a/apps/as/src/entities/esntl/model/esntl-interface.ts b/apps/as/src/entities/esntl/model/esntl-interface.ts
new file mode 100644
index 000000000..74f77ba72
--- /dev/null
+++ b/apps/as/src/entities/esntl/model/esntl-interface.ts
@@ -0,0 +1,25 @@
+/** 필수첨부파일관리 트리 조회 응답 DTO */
+export interface EsntlAtchFileMngTreeResponseDto {
+  /** 필수첨부파일아이디 */
+  esntlAtchFileId: string;
+  /** 문서구분공통코드 */
+  docSeComCd: string;
+  /** 필수첨부파일명 */
+  esntlAtchFileNm: string;
+  /** 필수첨부여부 ("Y" | "N") */
+  esntlAtchYn: "Y" | "N";
+  /** 필수첨부파일비고 (파일형식 등) */
+  esntlAtchFileRmrk: string;
+}
+
+/** 필수첨부파일관리 조회 파라미터 */
+export interface EsntlAtchFileMngSearchParams {
+  /** 문서구분공통코드 (예: "INSTL") */
+  docSeComCd: string;
+}
+
+/** 필수첨부파일관리 서비스 인터페이스 */
+export interface EsntlAtchFileMngService {
+  /** 필수첨부파일 트리 조회 */
+  findTree(params: EsntlAtchFileMngSearchParams): Promise<EsntlAtchFileMngTreeResponseDto[]>;
+}
diff --git a/apps/as/src/pages/instl-sncn/ui/cnfm-regist-page.tsx b/apps/as/src/pages/instl-sncn/ui/cnfm-regist-page.tsx
index 6424f9f17..866b37a8c 100644
--- a/apps/as/src/pages/instl-sncn/ui/cnfm-regist-page.tsx
+++ b/apps/as/src/pages/instl-sncn/ui/cnfm-regist-page.tsx
@@ -5,7 +5,7 @@ import { useRouter } from "next/navigation";
 
 import { useQuery } from "@tanstack/react-query";
 import axios from "axios";
-import { type HttpResponse,Upload } from "tus-js-client";
+import { type HttpResponse, Upload } from "tus-js-client";
 
 import { AUTH_USER_ID, CLAIM_NAME, ENDPOINT, PROXY_HOST } from "@/shared/config";
 import { getCookie, setCookie } from "@/shared/lib";
@@ -15,6 +15,10 @@ import type { CklstTreeNode } from "@/entities/cklst";
 import { cklstMngService } from "@/entities/cklst";
 import type { CnstpSeMngTreeDto } from "@/entities/cnstp";
 import { cnstpService } from "@/entities/cnstp";
+import {
+  esntlAtchFileMngService,
+  type EsntlAtchFileMngTreeResponseDto,
+} from "@/entities/esntl";
 import {
   INSTL_SNCN_REGISTER_SELECTION_KEY,
   InstlSncnApi,
@@ -42,34 +46,19 @@ type BzAmtRow = {
   thtiDsgn: string;
 };
 
-type RequiredAttachKey =
-  | "applyForm"
-  | "planGoalYear"
-  | "adequacyReview"
-  | "supervisionCost"
-  | "costBreakdown"
-  | "designDrawing"
-  | "etc";
+type RequiredAttachKey = string;
 
 type RequiredAttachItem = {
   key: RequiredAttachKey;
-  label: string;
+  esntlAtchFileNm: string;
+  esntlAtchYn: "Y" | "N";
+  esntlAtchFileRmrk: string;
   atflCd: string;
   atflId: string;
   fileName: string;
   uploading: boolean;
 };
 
-const REQUIRED_ATTACHMENTS: Array<{ key: RequiredAttachKey; label: string }> = [
-  { key: "applyForm", label: "인가신청서" },
-  { key: "planGoalYear", label: "계획수립 기준 및 목표연도 계획" },
-  { key: "adequacyReview", label: "하수도 시설계획 적정성 검토 결과" },
-  { key: "supervisionCost", label: "관로설계시설물 감리비용 산출 계획서" },
-  { key: "costBreakdown", label: "사업비 내역서" },
-  { key: "designDrawing", label: "설계도면" },
-  { key: "etc", label: "기타 첨부자료" },
-];
-
 const emptyScale = (): BzScaleRow => ({ bscPl: "", budgetReflct: "", thtiDsgn: "" });
 const emptyAmt = (): BzAmtRow => ({ bscPl: "", budgetReflct: "", thtiDsgn: "" });
 
@@ -99,6 +88,7 @@ const ReadCell = ({ value }: { value: string | number }) => (
 /* ------------------------------------------------------------------ */
 function CnfmRegistPage() {
   const router = useRouter();
+  const [docSeComCd] = useState("INSTL");
   const [taskSeComCdNm, setTaskSeComCdNm] = useState("재이용수");
   const [taskSeComCd, setTaskSeComCd] = useState("RE");
 
@@ -139,32 +129,39 @@ function CnfmRegistPage() {
   const [etcNoticeOpen, setEtcNoticeOpen] = useState(true);
 
   /* ── 필수 첨부파일 ── */
-  const [requiredFiles, setRequiredFiles] = useState<Record<RequiredAttachKey, RequiredAttachItem>>(() =>
-    REQUIRED_ATTACHMENTS.reduce(
-      (acc, item) => {
-        acc[item.key] = {
-          key: item.key,
-          label: item.label,
-          atflCd: "",
-          atflId: "",
-          fileName: "",
-          uploading: false,
-        };
-        return acc;
-      },
-      {} as Record<RequiredAttachKey, RequiredAttachItem>,
-    ),
-  );
-  const requiredFileInputRefs = useRef<Record<RequiredAttachKey, HTMLInputElement | null>>({
-    applyForm: null,
-    planGoalYear: null,
-    adequacyReview: null,
-    supervisionCost: null,
-    costBreakdown: null,
-    designDrawing: null,
-    etc: null,
+  const { data: requiredAttachmentDefs = [] } = useQuery<EsntlAtchFileMngTreeResponseDto[]>({
+    queryKey: ["esntlAtchFileTree", docSeComCd],
+    queryFn: () => esntlAtchFileMngService.findTree({ docSeComCd }),
+    enabled: Boolean(docSeComCd),
+    staleTime: Infinity,
   });
 
+  const [requiredFiles, setRequiredFiles] = useState<Record<RequiredAttachKey, RequiredAttachItem>>({});
+  const requiredFileInputRefs = useRef<Record<RequiredAttachKey, HTMLInputElement | null>>({});
+
+  useEffect(() => {
+    if (requiredAttachmentDefs.length === 0) return;
+
+    setRequiredFiles((prev) => {
+      const next: Record<RequiredAttachKey, RequiredAttachItem> = {};
+      for (const item of requiredAttachmentDefs) {
+        const key = item.esntlAtchFileId;
+        const prevItem = prev[key];
+        next[key] = {
+          key,
+          esntlAtchFileNm: item.esntlAtchFileNm,
+          esntlAtchYn: item.esntlAtchYn,
+          esntlAtchFileRmrk: item.esntlAtchFileRmrk,
+          atflCd: prevItem?.atflCd ?? "",
+          atflId: prevItem?.atflId ?? "",
+          fileName: prevItem?.fileName ?? "",
+          uploading: prevItem?.uploading ?? false,
+        };
+      }
+      return next;
+    });
+  }, [requiredAttachmentDefs]);
+
   const uploadRequiredFile = (file: File, key: RequiredAttachKey) => {
     setRequiredFiles((prev) => ({
       ...prev,
@@ -236,9 +233,9 @@ function CnfmRegistPage() {
   const cklstRowRefs = useRef<Record<string, HTMLTableRowElement | null>>({});
 
   const { data: cklstTree = [] } = useQuery<CklstTreeNode[]>({
-    queryKey: ["cklstTree", "INSTL", taskSeComCd],
-    queryFn: () => cklstMngService.findTree({ docSeComCd: "INSTL", taskSeComCd }),
-    enabled: Boolean(taskSeComCd),
+    queryKey: ["cklstTree", docSeComCd, taskSeComCd],
+    queryFn: () => cklstMngService.findTree({ docSeComCd, taskSeComCd }),
+    enabled: Boolean(docSeComCd) && Boolean(taskSeComCd),
     staleTime: Infinity,
   });
 
@@ -479,7 +476,7 @@ function CnfmRegistPage() {
 
   /* ── 검증 ── */
   function fnValidation(mode: "SAVE" | "PRESENTN") {
-    /*
+    
     if (!bzNm.trim()) {
       alert("사업명을 입력하세요.");
       return false;
@@ -506,9 +503,19 @@ function CnfmRegistPage() {
       alert("체크리스트를 모두 체크하세요.");
       return false;
     } 
-    // 저장 시: 사용 항목(Y)은 검토 결과가 반드시 예(Y)여야 함 
-   */
+    // 저장 시: 필수 첨부파일(esntlAtchYn=Y) 업로드 여부 검증
     if (mode === "SAVE") {
+      const missingRequiredFile = requiredAttachmentDefs.find((item) => {
+        if (item.esntlAtchYn !== "Y") return false;
+        const uploaded = requiredFiles[item.esntlAtchFileId];
+        return !(uploaded?.atflCd && uploaded?.atflId);
+      });
+      if (missingRequiredFile) {
+        alert(`${missingRequiredFile.esntlAtchFileNm} 파일을 첨부하세요.`);
+        return false;
+      }
+
+      // 저장 시: 사용 항목(Y)은 검토 결과가 반드시 예(Y)여야 함
       const invalidYesRow = cklstRows.find(
         (row) => row.bchckUseYn === "Y" && checkResults[cklstKey(row)] !== "Y",
       );
@@ -1116,39 +1123,58 @@ function CnfmRegistPage() {
               </tr>
             </thead>
             <tbody>
-              {REQUIRED_ATTACHMENTS.map(({ key, label }) => (
-                <tr key={key}>
-                  <td className="pl-2 text-left">{label}</td>
-                  <td>hwp/pdf</td>
-                  <td>
-                    <div className="flex items-center justify-center gap-2">
-                      <input
-                        type="text"
-                        placeholder="첨부문서를 올려주세요"
-                        className="cnfm-input flex-1"
-                        value={requiredFiles[key]?.uploading ? "업로드 중..." : requiredFiles[key]?.fileName || ""}
-                        readOnly
-                      />
-                      <input
-                        ref={(el) => {
-                          requiredFileInputRefs.current[key] = el;
-                        }}
-                        type="file"
-                        className="hidden"
-                        onChange={(e) => handleRequiredFileChange(key, e)}
-                      />
-                      <button
-                        type="button"
-                        className="cnfm-btn-search text-[1.2rem]"
-                        onClick={() => requiredFileInputRefs.current[key]?.click()}
-                        disabled={requiredFiles[key]?.uploading}
-                      >
-                        {requiredFiles[key]?.uploading ? "업로드중" : "첨부하기"}
-                      </button>
-                    </div>
+              {requiredAttachmentDefs.length === 0 ? (
+                <tr>
+                  <td colSpan={3} className="cnfm-td-empty">
+                    조회된 필수 첨부파일 항목이 없습니다.
                   </td>
                 </tr>
-              ))}
+              ) : (
+                requiredAttachmentDefs.map((item) => {
+                  const key = item.esntlAtchFileId;
+                  const requiredFile = requiredFiles[key];
+                  const fileFormat = (item.esntlAtchFileRmrk || "").replaceAll(",", "/") || "-";
+
+                  return (
+                    <tr key={key}>
+                      <td className="pl-2">
+                        <div className="w-full text-left">
+                          {item.esntlAtchFileNm}
+                          {item.esntlAtchYn === "Y" ? <span className="ml-1 text-red-500">*</span> : null}
+                        </div>
+                      </td>
+                      <td>{fileFormat}</td>
+                      <td>
+                        <div className="flex items-center justify-center gap-2">
+                          <input
+                            type="text"
+                            placeholder="첨부문서를 올려주세요"
+                            className="cnfm-input flex-1"
+                            value={requiredFile?.uploading ? "업로드 중..." : requiredFile?.fileName || ""}
+                            readOnly
+                          />
+                          <input
+                            ref={(el) => {
+                              requiredFileInputRefs.current[key] = el;
+                            }}
+                            type="file"
+                            className="hidden"
+                            onChange={(e) => handleRequiredFileChange(key, e)}
+                          />
+                          <button
+                            type="button"
+                            className="cnfm-btn-search text-[1.2rem]"
+                            onClick={() => requiredFileInputRefs.current[key]?.click()}
+                            disabled={requiredFile?.uploading}
+                          >
+                            {requiredFile?.uploading ? "업로드중" : "첨부하기"}
+                          </button>
+                        </div>
+                      </td>
+                    </tr>
+                  );
+                })
+              )}
             </tbody>
           </table>
         </div>
diff --git a/apps/as/src/shared/config/api.ts b/apps/as/src/shared/config/api.ts
index 440f3e86b..bb6c53f53 100644
--- a/apps/as/src/shared/config/api.ts
+++ b/apps/as/src/shared/config/api.ts
@@ -6,6 +6,7 @@ export const ENDPOINT = {
   AS_COMMON_SERVICE: {
     ACNTG_SE: "/as-common-service/api/v1/acntg-se",
     CNSTP_SE: "/as-common-service/api/v1/cnstp-se",
+    ESNTL_ATCH_FILE: "/as-common-service/api/v1/esntl-atch-file",
   },
   AS_INSTL_SERVICE: {
     INSTL_SNCN: "/as-instl-service/api/v1/instl-sncn",