An optical measuring device includes: an emission device configured to emit a scanning light, of which an optical axis parallelly moves, to an object; a light receiving element configured to perform photoelectric conversion with respect to the scanning light after passing over the object; a calculation device configured to calculate, from a voltage wave obtained from time change of an electrical signal that is output by the light receiving element, a distance corresponding to a time range from a first edge with respect to a voltage value where the scanning light is not interrupted by the object and a second edge with respect to a voltage value where the scanning light is interrupted by the object, when a part of the scanning light is interrupted by the object for the time range.