An automatic exposure control circuit which controls the shutter speed in accordance with the output of a light measuring circuit including a photodetector which detects the level of scene brightness. The output of the photodetector is memorized by a memorizing capacitor and the shutter speed control circuit is operated in accordance with the memorized output. The memorized level is shifted to a predetermined level when the memorized level is below a predetermined level which corresponds to a limit of scene brightness which can be photographed. A switching circuit and a shifting circuit connected therewith are connected with an end of the memorizing capacitor so that the level of the memorized output may be shifted by the shifting circuit when the level memorized by the capacitor is below a predetermined level. The shutter speed is therefore determined regardless of the scene brightness when the level of the scene brightness is below a predetermined level.