1. A three-dimensional measuring device comprising: an irradiation means capable of irradiating light for three-dimensional measurement onto a measurement object having a first area formed by objects under inspection and a second area forming a standard for measurement of height of the first area, an imaging means capable of imaging light reflected from the measurement object irradiated by the light, and an image processing means for three-dimensional measurement of the measurement object based on image data imaged by the imaging means; wherein the three-dimensional measuring device: performs first image processing by imaging for a first exposure time such that brightness of a location corresponding to a bright part as either the first area or the second area is not saturated; performs second image processing by imaging for a second exposure time corresponding to a time insufficiency, the insufficiency being between the first exposure time and a certain exposure time appropriate for measurement of a dark part of the first area or the second area; performs image preparation processing by combining a location of brightness non-saturation of imaging data obtained by the first image processing and a location of brightness non-saturation of imaging data obtained by the second image processing to prepare image data for three-dimensional measurement having no brightness saturation in the first area and the second area; and performs three-dimensional measurement based on the image data for three-dimensional measurement.