1. A three-dimensional image measuring device comprising: a hologram adapted to be subjected to multi-exposure such that when reproduced light is irradiated, a plane light image is formed at a plurality of different positions in a depth direction corresponding to a rotational angle of the hologram itself; a light source for irradiating the reproduced light on the hologram; hologram rotation drive means for imaging the plane light image at positions in the depth direction according to each rotational angle by rotationally driving the hologram at a plurality of different rotational angles; an object adapted to be measured being disposed in a space where the plane light image is formed; light receiving means including a plurality of two-dimensional-arranged light receiving elements, for sequentially measuring the strength of scattered light of the plane light image imaged on a surface of the object as the hologram is rotated by the hologram rotation drive means; and distance measuring means for measuring the distance to the object based on an output of each light receiving element of the light receiving means.