Provided is a three-dimensional measurement device that makes it possible to dramatically increase measurement accuracy when making a three-dimensional measurement using the phase shift method. A substrate inspection device 1 is provided with the following: an illumination device 4 that projects a predetermined stripe pattern from the oblique upper direction onto the surface of a printed substrate2; a camera 5 that captures images of the portion atop the printed substrate 2 where the stripe pattern is projected; and a control device 6 that performs various types of control, image processing,and arithmetic processing inside the substrate inspection device 1. Further, the stripe pattern projected onto the printed substrate 2 is moved, the moving stripe pattern is imaged multiple times, thebrightness values of each pixel in a series of captured image data items are added together, for every pixel, and an average value for each pixel is calculated.