Abstract: An object detection device for detecting an object includes a light receiving section that has a light receiving surface in which a plurality of light receiving elements capable of receiving incident light including reflected light of emitted radiated light are arranged in a plane, and that outputs a first light receiving signal according to a light receiving state of the light receiving element in a first area, when a predetermined usable area in the usable areas on the light receiving surface is referred to as a first area, an image acquisition part that acquires an ambient light image indicating a light receiving intensity of ambient light using the first light receiving signal, and a malfunction detection part that detects a malfunction of the light receiving element in the first area using the ambient light image.