To improve performance and to miniaturize a device by correcting the aberration of an optical system.

An optical pickup 7 is provided with a light emitting element 14 moving in the radial direction of a disk recording medium 100 to emit a laser beam toward the same, an objective lens 13 for focusing the laser beam emitted from the light emitting element on the recording track of the disk recording medium, and a light receiving element 18 for receiving the laser beam reflected on the disk recording medium as a return light. In this case, an aberration correction optical element 17 is arranged in the optical path of the laser beam between the light emitting element and the objective lens, and the aberration correction optical element is provided with a liquid crystal element 19 having liquid crystal layers 26 on a pair of opposing protective inter-plates 21 to correct the spherical aberration, and a diffraction element 20 disposed on at least one protective plate of the liquid crystal element to correct color aberration.