PURPOSE: To attain forming in compactness and reducing of a cost, by providing a lock/unlock mechanism part, panic-proof mechanism part, and an electric unlock mechanism part.

CONSTITUTION: A trigger bolt 4 is sunk to tilt a stopper 9 when a door is closed, and a slider 10 is moved to turn a can plate 18. Next, a dead bolt 25 is protruded, and a guard lever 32 is engaged with the bolt 25 to be placed in a lock condition. At unlock time by panic-proof, a turn lever 57 is turned by moving an inner side retractor 41 when an inner side hub 37 is turned. Next, the plate 18 is turned in an unlock direction and the bolt 25 is sunk by releasing engagement of the bolt 25 with the lever 32. At unlock time by electricity, when a solenoid is excited, a locking block and an outer side retractor are disengaged, an outer side hub is rotated, the retractor is moved, and a panic slider 52 is moved. Then, unlocking is operated similarly to that by the panic- proof.