THREE-DIMENSIONAL SHAPE MEASURING DEVICE, REFERENCE SURFACE POSITION ADJUSTMENT METHOD THEREFOR, AND MEASUREMENT MODE SWITCHING METHOD THEREFOR

A three-dimensional shape measuring device includes a holder that changes the reference light path length in response to temperature change, and a temperature adjusting unit that adjusts a temperature of the holder to a target temperature, so as to make a measurement light path length equal to a reference light path length with high accuracy at low cost regardless of a temperature of an installation environment. A three-dimensional shape measuring device includes a temperature adjusting unit that adjusts the temperature of the holder and a temperature control unit that controls the temperature adjusting unit so as to selectively switch a measurement mode between a first measurement mode in which the reference light path length is made equal to a measurement light path length and a second measurement mode in which the reference light path length is made different from the measurement light path length.