To provide a device for detecting lock condition of a door, which can surely prevent a contact point failure by preventing intrusion of foreign materials into a contact point part and generation of rust therein.

A door lock device 1 is structured of: a lock lever (a moving member)2 for locking a door by moving with the door closing operation so as to lock a hook part (a lock claw) 20 with a case (a wall side member) 3; a piston 6 having a through-hole (an engagement part)60 to be engaged with a tip of the lock lever 2 and capable of going ups and downs inside a guide member 5 provided in a wall so as to be moved downward by the lock lever 2 through the through-hole 60 when locking the door with the lock lever 2; and contact points 5A and 6A for monitoring lock condition of the door, which is provided to be short-circuited by action of a lower end of the piston 6 when locking the door inside a cylindrical part of the guide member 5 so as to detect the lock condition of the door for monitoring.