A moving obstacle detecting device detects moving objects, may be applied in the field of autonomous vehicles, intelligent robots, video monitoring system and similar systems. The device includes an optical flow extracting unit 1 for extracting optical flows for the respective local regions in the measured images, an focus of expansion (F.O.E.) calculating unit for calculating an F.O.E. of a straight line extended by the extracted optical flows, and a moving obstacle detecting unit for analyzing a temporal change of the calculated F.O.E. to judge the presence of the moving obstacle when the temporal positional change is larger than a predetermined variation quantity.