To provide a preventing means capable of easily preventing life component parts of a shutter from being broken and preventing a drive motor from failing at a low cost when a slat curtain is interrupted by an obstacle during its descent.

This opening/closing control device for a shutter is provided with a drum Z winding or delivering a slat curtain, a drive motor 4 for rotatively driving the drum 2, and a pulse plate 17 rotated interlockingly with the drive motor 4. The rotating state of the drive motor 4 is detected by a photo-interrupter 8a provided corresponding to the pulse plate 17. A control device 5 stops the drive motor 4 when a change of the rotating state of the drive motor 4 is detected based on a pulse signal from the photo-interrupter 8a.