To provide a landing door locking device for an elevator or the like that can avoid the danger of falling into an elevator shaft by mistake by limiting the opening width of a landing door in case of a car not being in a car upper boarding position at the time of trying to open the landing door for inspection-repair work of the elevator or the like.

Even in case of trying to open a landing door 2 when a car 6 is not in a car upper boarding position, the landing door 2 is opened only by specified small opening width by the function of a stopper 9a of a landing door locking means 9, and a lock release means (cam) 11 is provided to release a restriction on the opening width of the landing door 2 by the landing door locking means 9, according to the stop position of the car 6. At the time of the car 6 being in the car upper boarding position or in case of operating a landing locking means 3 at the landing on the lowermost floor, the locked state by the landing door locking means 9 is released to allow a person to pass through.