To provide an emergency unlocking type lock device which is not bulky, is simply structured, and is capable of reducing costs.

For the emergency unlocking type lock device of this invention, a door lock 3 is attached to a sliding door 2 arranged at an entrance 1 of a sickroom or the like, and a locking metal fitting 5 is attached to an edge part 4 of the entrance 1. Then, the door lock 3 and the locking metal fitting 5 are connected in such a state that opening is possible only for a prescribed amount with a chain 6. The door lock 3 comprises a stopper 25 for detachably locking the chain 6 by dead weight, a drive part 26 for driving the stopper 25, and a communication part 27 for receiving emergency signals transmitted by radio on the basis of detection of an emergency by an emergency sensor 54 and sending drive instruction signals to the drive part 26. The drive part 26 releases locking of the chain 6 by the stopper 25 when the drive instruction signals are received.