To provide a water-tight door which is inexpensive and exerts high water tightness by a simple operation.

A water-tight door comprises: a door frame 2 having a door opening 2a; and a door plate 1 holding the door opening 2a on the door frame 2 through a hinge in a freely openable and closable way. The water-tight door has a locking member 13 having two selectable positions, i.e. a lock position at which the door plate 1 is locked in the door frame 1 and an unlock position at which the locking of the door plate 1 in the door frame 2 is released, a handle 3a arranged on the door plate 1 in a movable way and held on a connection shaft 10 arranged on the door plate 1 in a freely rotatable way, a striker 8 fixed to the handle 3a, and a handle 4a having striking pieces 6 and 7 to be impinged on the striking face of the striker 8 and held on the connection shaft 10 in a freely rotatable way. The locking member 13 is moved to the lock position by transmitting the striking force produced when the striking face of the striker is struck to the locking member 13 through a link member 12, leading to exertion of required water tightness.