A distance measurement device includes: an emission and exposure controller which controls emission timing and an emission period of irradiation light for an emitter and controls exposure timing and an exposure period of reflected light for a solid-state image sensor; and a data processor which includes a calculator that calculates distance data and light intensity data based on signals of pixels outputted by a light receiver. The emission and exposure controller controls the exposure timing to perform exposure to reflected light from a first distance and not to perform exposure to reflected light from a second distance longer than the first distance in a distance measurement range. The data processor includes a determination unit which determines reliability of the distance data in accordance with a signal amount of the light intensity data for each of the pixels.