To provide a lock reduced in projecting dimension from a door surface, easy to be handled, having large strength and to be used for wide use by solving the problem wherein a lock reduced in projecting dimension from a door surface is required, in regards to a maintenance door provided in a wall surface of a corridor and a fire shutter normally opened, and wherein a case handle lock and several kinds of lock for sliding doors are also hard to handle or formed with large projection or strength thereof is not enough.

This lock is formed so that a latch bolt is pulled inside by raising a knob from both sides of the door. With this structure, projecting dimension of this lock from the door surface when the lock is not operated is reduced.