To attain the reduction of a manufacturing cost, the facilitation of a combination or the like.

In a stopper disengaging mechanism for a lock with a dead bolt with an engaging head section projected from the front of a lock case, a top joint disposed so that a driving arm is engaged with the rear end section of the dead bolt, a stopper being disposed on the reverse side to the place of the top joint and engaging the rear end section of the dead bolt and a pushing means rotating the stopper in the direction of a disengagement by the driving force of the top joint when the top joint is turned, a movable pin installed under a vertical state to a guide block fixed on a supporting drum section as the rear end section of the dead bolt is used as the pushing means.