diff --git a/Assets/Scripts/Mechanics/PlayerController.cs b/Assets/Scripts/Mechanics/PlayerController.cs
index 5f03c31..f513c92 100644
--- a/Assets/Scripts/Mechanics/PlayerController.cs
+++ b/Assets/Scripts/Mechanics/PlayerController.cs
@@ -155,13 +155,12 @@ namespace Platformer.Mechanics
 
             // PD 지시 2026-05-07 — 낙사 시 복귀할 안전 위치 추적
             if (IsGrounded) LastGroundedPosition = transform.position;
-
-            // BT5-Dev #38 — 표준 Drop-Through: 점프 상승(velocity.y > 0) Layer 16 통과·하강(≤0) 충돌 ON
-            const int JUMP_THROUGH_LAYER = 16;
-            bool rising = velocity.y > 0.05f;
-            Physics2D.IgnoreLayerCollision(13, JUMP_THROUGH_LAYER, rising);
         }
 
+        // BT5-Dev #39 — 점프 시작 시 Coroutine으로 0.3초 동안 Layer 16 통과 유지 (Physics step 지연 차단)
+        const int JUMP_THROUGH_LAYER = 16;
+        bool _jumpThroughActive;
+
         void UpdateJumpState()
         {
             jump = false;
@@ -171,6 +170,8 @@ namespace Platformer.Mechanics
                     jumpState = JumpState.Jumping;
                     jump = true;
                     stopJump = false;
+                    // BT39 — 점프 시작 시 즉시 IgnoreLayerCollision 활성 + Coroutine으로 0.3초 유지
+                    if (!_jumpThroughActive) StartCoroutine(JumpThroughRoutine());
                     break;
                 case JumpState.Jumping:
                     if (!IsGrounded)
@@ -192,6 +193,15 @@ namespace Platformer.Mechanics
             }
         }
 
+        System.Collections.IEnumerator JumpThroughRoutine()
+        {
+            _jumpThroughActive = true;
+            Physics2D.IgnoreLayerCollision(13, JUMP_THROUGH_LAYER, true);
+            yield return new WaitForSeconds(0.3f);
+            Physics2D.IgnoreLayerCollision(13, JUMP_THROUGH_LAYER, false);
+            _jumpThroughActive = false;
+        }
+
         protected override void ComputeVelocity()
         {
             if (jump && IsGrounded)