PURPOSE: To obtain a hologram for scanning easily by making one of divided optical beam incident upon a mirror rotating at θ of speed onto a medium through a rotating optical system, which is linked with said mirror and is rotating at 2θ of speed, together with another part of the divided beam.

CONSTITUTION: A beam B1, which is the one of the beams B1 and B2 irradiated from the same laser light source LS, is made incident upon a mirror M1. The mirror M1 is made to rotate around an axis AX1, which is perpendicular to the beam in the reflection plane, at θ of rotating speed. A reflecting ray is made incident upon an optical system OPS, which is linked with the mirror M1 and is rotating in the same direction with M1 at 2θ of rotating speed, and exiting ray from this system is exposed onto a desired place on a hologram recording medium body HR together with the another part B2 of the beam. Then, as the body HR is made to rotate around an axis AX2 at of rotating speed, a hologram shifted a position of a center of a spherical wave successively on a circumference is recorded. The system OPS is constituted of the mirror M1 and a mirror M2, and is rotated together with a circular disk DS.