To provide a lock device which can eliminate lateral pressure of a dead bolt, working in a door closing direction due to application of an external force, to thereby prevent erroneous operation of the dead bolt caused by the lateral pressure.

The lock device 100 is formed of: an engaging rod 35 arranged in a door 15 in a manner protrudable from a butt end 15a of the same; an energizing spring 37 for drawing the engaging rod 35 away from the butt end 15a to the interior of the door 15; a strike 21 arranged on a door frame 13 in a manner facing the butt end 15a of the closed door, and accommodating the engaging rod 35 protruding from the butt end 15a; a movable magnet 39 attached to the engaging rod 35; and a fixed magnet 41 arranged on the door frame 13, for facing the movable magnet 39 when the door is closed, and drawing the engaging rod 35 out of the butt end 15a by a magnetically attractive force, to thereby allow the engaging rod 35 to enter the strike 21.