To sufficiently protect privacy of a handicapped person and an aged person and perform unlocking from the indoor side by the handicapped person or the like at the time of emergency by simple operation even in a wheelchair or from the outdoor side by a nurse.

The protection device can be unlocked in a space partitioned by a sliding door 2 from the inside by a handicapped person and from the outside at the time of emergency. The sliding door 2 has a lock handle 5 provided with a main shaft 4 which penetrates the sliding door 2 and makes frequent appearances in the thickness direction, at the time of locking, the main shaft 4 of the lock handle 5 is projected to the sliding door 2 outside, and at the time of unlocking the main shaft 4 is retracted to a sliding door face.