PURPOSE: To surely unlock a lock by moving a retractor and a panic slider so as to rotate a cam plate interlocked with a dead bolt through a rotation lever in an unlocking direction by rotating a hub in either directions.

CONSTITUTION: When a hub 13 is rotated by a lever within a room, either one of flanges 14A, 14B presses a vertical wall 17A or a wall 17B so as to move a retractor 15 rightwards. Then, when the retractor 15 is moved rightwards, a protrusion piece 28 of a slider 25 is pressed by a vertical wall 18 and moved rightward and a rotation lever 30 is rotated clockwise about a pin 31 by a rightward movement of a shaft 29. A connection lever 34 engaged with a shaft part 33 of the lever 30 pushes a drive piece 3 to a right direction and a cam plate 2 is rotated counterclockwise and a dead bolt 7 engaged with the drive piece 3 is sunk into a door 1 for unlocking a lock.