PURPOSE: To make it possible to unlock easily a guard opening by turning a reverse guide plate freely to change a direction when a door is opened in a state of a guard opening, and making a latch-stopper removable from a stopper case when the guard opening is widely opened.

CONSTITUTION: In a latch-stopper 1, the base is held on the end of a stopper case 4 sliding toward the inside of a stile 3 from a door front surface 2. In a reverse guide plate 9, it is so constituted that it turns in a jamb 15 of the end of a stopper-pin-lever 13. When the stopper-pin-lever 13 is lifted to open the door in a state to insert in the latch-stopper in the event of door-opening, the reverse guide plate 9 turns freely to change the direction by ordinary gravity in a chain from the rear, and the latch-stopper 1 is removed from the stopper case 4 to widen a guard opening. According to the constitution, it can be eliminate the troublesomeness for unlocking a guard lock after closing the door.