To improve the reading performance of an information signal recorded in a disk recording medium while reducing manufacturing costs and simplifying an optical system.

This device is provided with a light emitting element 9 having two light emitting points 9a and 9b for emitting laser beams of different wavelengths, a diffraction element 10 for separating a laser beam into main and sub luminous fluxes, and a light receiving element 14 for receiving a laser beam reflected by a disk recording medium 100. First to third light receiving areas 15, 16, 17 are formed as at least three areas for receiving laser beams are formed in the light receiving element, at least the three light receiving areas are formed as divided areas divided into a plurality of areas, a part of the three light receiving areas is used as a common light receiving area for receiving return light reflected by the disk recording medium of a different kind, the arraying direction of the first and second light receiving areas are matched with the tangential direction of the disk recording medium, the arraying direction of the second and third light receiving areas are matched with the polarizing direction of a laser beam, and the polarizing direction is set different from the radial direction of the disk recording medium.