To provide a three-dimensional visual sensor that can acquire a clearer slit image with little change of luminance at the time of measuring shape by an optical cutting method and can enlarge the adaptive range of objects.

With slit light L1 emitted from a laser 3, an object W is irradiated by a first mirror M1. Second and third mirrors M2, M3 are provided in symmetric positions with an optical path of the slit light L1 as the center. Mutually different return light L2, L3 respectively reflected by the surface of the object W in the symmetric directions with the optical path of the slit light L1 as the center are composed by a beam splitter 5 and received by a CCD camera 6. An image (slit image) of the slit light L1 on the surface of the object W is obtained on the basis of composite return light L4 of the mutually different return light L2, L3.