A three-dimensional measuring device includes an irradiation device configured to irradiate and switch among a multiplicity of light patterns having different periods and having a striped light intensity distribution on at least a measurement object, a camera having an imaging element capable of imaging reflected light from the measurement object irradiated by the light pattern, a rack configured to cause relative change in positional relationship between the imaging element and the measurement object, and a control device configured to perform three-dimensional measurements based on image data imaged by the camera. The control device performs the three-dimensional measurements by performing a phase shift method calculation of height data as a first height data for each pixel unit of image data based on a multiply phase-shifted image data obtained by irradiating on a first position a multiply phase-shifted first light pattern having a first period.