Disclosed herein is an apparatus for measuring the shape of a 3D object using an interferometer. The apparatus includes a light source unit, a beam splitter, a reference mirror, an actuator, an image pickup device, and a control unit. The light source unit emits light. The beam splitter divides the light from the light source unit. The reference mirror reflects light as a reference beam. The actuator moves the reference mirror. The image pickup device acquires a plurality of interference patterns by causing the reflected beam and the reference beam to interfere with each other. The control unit measures the shape of the object from the acquired interference patterns, outputs reference mirror drive signals to the actuator, and issues an image capture command at the end of image capture time that is shorter than settling time.