There is provided a three-dimensional measurement device that uses two different lights of different wavelengths to expand the measurement range and improve the measurement efficiency. The three-dimensional measurement device 1 includes a polarizing beam splitter 20 configured to split a predetermined incident light into two polarized lights having polarizing directions orthogonal to each other, to radiate one of the two polarized lights as a measurement light to a work W and the other as a reference light to a reference surface 23, and to recombine the two polarized lights to a combined light and emit the combined light; a first projection optical system 2A configured to cause a first light having a first wavelength to enter a first surface 20a of the polarizing beam splitter 20; a second projection optical system 2B configured to cause a second light having a second wavelength to enter a second surface 20b of the polarizing beam splitter 20; a first imaging system 4A configured to take an image of the first light emitted from the second surface 20b of the polarizing beam splitter 20; and a second imaging system 4B configured to take an image of the second light emitted from the first surface 20a of the polarizing beam splitter 20.