The objective of the present invention is, using an optical system which performs adjustment, to allow a reference beam optical system to be adjustable with high accuracy. The present invention is an optical information playback device which plays back information that has been recorded using angle-multiplexing holography on an optical information recording medium, said optical information playback device being provided with: a light source for generating a reference light; a first actuator which varies the angle of the reference light that is incident to the optical information recording medium; phase conjugate generation means configured by combining a condenser lens which generates phase-conjugated beams of light that has been transmitted through the optical information recording medium, and a movable mirror; a second actuator which drives the movable mirror; and a reference light measurement unit which measures divergence and convergence of the reference light from the phase conjugate generation means.