To reduce the number of components to the utmost.

In a temporary locking and unlocking device for a lock, one temporary locking piece is built in a lock case so that a locking part can be engaged with an engaging retainer part of a protrusive engaging member which is built in a supporting member for the lock case; a central part is fitted to the temporary locking piece in such a manner as to be wound around a fixing shaft; and a return spring is integrally annexed in a state wherein both front and rear ends each abut on the temporary locking piece. In the device, when a pushing piece, which protrudes inward from a window of the lock case, ascends/descends in the closing of a door, the temporary locking piece moves upward or downward while maintaining a horizontal state due to the movement of the pushing piece, and the locking part is engaged with/disengaged from the engaging retainer part of the protrusive engaging member.