A three-dimensional measurement device includes: an optical system that splits incident light into two lights, radiates one of the two lights as measurement light to a measurement object and the other as reference light to a reference surface, and recombines the two lights to emit combined light; a first irradiation unit that emits first light entering the optical system; a second irradiation unit that emits second light entering the optical system; a first imaging unit into which output light that is obtained from the first light and is emitted from the optical system enters; a second imaging unit into which output light that is obtained from the second light and is emitted from the optical system enters; and an image processor that executes three-dimensional measurement of the measurement object, based on interference fringe images taken by the first imaging unit and the second imaging unit.