diff --git a/src/main/java/com/eactive/apim/portal/approval/statemachine/ProcessingState.java b/src/main/java/com/eactive/apim/portal/approval/statemachine/ProcessingState.java
index cc08b9e..2b8d0b0 100644
--- a/src/main/java/com/eactive/apim/portal/approval/statemachine/ProcessingState.java
+++ b/src/main/java/com/eactive/apim/portal/approval/statemachine/ProcessingState.java
@@ -23,6 +23,9 @@ public class ProcessingState implements ApprovalState {
             case DENY:
                 handleDeny(approval, options);
                 break;
+            case CANCEL:
+                handleCancel(approval, options);
+                break;
             default:
                 logger.warn("Invalid event {} for ProcessingState in approval {}", event, approval.getId());
                 throw new UnsupportedOperationException("Invalid event for Processing state");
@@ -91,6 +94,38 @@ public class ProcessingState implements ApprovalState {
         }
     }
 
+    /**
+     * 신청자 취소. 심사중(PROCESSING)이라도 <b>아직 아무도 승인하지 않은</b> 경우에 한해 허용한다.
+     *
+     * <p>관리자가 결재 상세를 열어보기만 해도 REQUESTED → PROCESSING 으로 바뀌므로(admin
+     * {@code PortalApprovalManService.selectDetail}), 이 상태의 상당수는 실제로 결재가 진행된 것이
+     * 아니라 열람만 된 건이다. 그런 건이 취소 불가로 남으면 해당 인증키의 후속 신청(변경/해지)이
+     * 무기한 막힌다. 승인 이력이 하나라도 있으면 기존 정책대로 거절한다.</p>
+     */
+    private void handleCancel(Approval approval, Map<String, Object> options) {
+        boolean anyApproved = approval.getApprovers().stream()
+            .anyMatch(approver -> ApproverStatus.APPROVED.equals(approver.getApproverStatus()));
+        if (anyApproved) {
+            logger.warn("Cancel rejected for approval {} - already approved by at least one approver", approval.getId());
+            throw new UnsupportedOperationException("Cannot cancel approval already approved by an approver");
+        }
+
+        String approverId = (String) options.getOrDefault(ApprovalConstants.APPROVER, "");
+        if (!isAuthorizedApprover(approval, approverId, options)) {
+            logger.warn("Unauthorized cancel attempt for approval {} by {}", approval.getId(), approverId);
+            throw new UnauthorizedApprovalException("Unauthorized approver");
+        }
+
+        approval.getApprovers().forEach(approver -> {
+            approver.setApproverStatus(ApproverStatus.CANCELED);
+            approver.setApprovedDate(LocalDateTime.now());
+        });
+        approval.setApprovalDate(LocalDateTime.now());
+        getApprovalListener(options).rollback(approval);
+        approval.setApprovalStatus(new CanceledState());
+        logger.info("Approval {} cancelled in Processing state by {}", approval.getId(), approverId);
+    }
+
     @Override
     public String toString() {
         return ApprovalStatus.PROCESSING.toString();