To provide a rotation stop device for a crescent that stops a crescent in a locked state from rotating and saves the trouble to unlock the crescent, and further rapidly releases the crescent from being stopped from rotating.

The rotation stop device for a crescent stops a crescent 8, locked by rotating and engaging with a receiver 9 with a glass door 3 closed, from rotating. The rotation stop device 12 for a crescent is attached to the glass door 3, and a main body 12a thereof includes a stop member 13 capable of moving forward and backward, a driving part 14 driving the stop member 13, a control part 15 controlling the driving part 14, a communication part 17 receiving an instruction signal transmitted from a remote controller 16 by radio and sending it to the control part 15, and a power supply part 18 supplying electric power to respective parts. The stop member 13 stops the crescent 8 from rotating when moving forward and releases the crescent 18 from being stopped from rotating when moving backward. A solar battery 28 is connected to the power supply part 18.