To provide an optical pickup device capable of offset-adjusting focus error signals.

The device includes a light source 1 that emits light in a wavelength region suitable for recording and/or reproducing a relatively thin disk, an optical path switching means 27 that changes the traveling path of incident light, an objective lens 15 that converges the incident light so that an optical spot is formed on the recording face of the disk 19, and an optical detector 28 that consists of four light receiving areas which, arranged in the shape of two rows and two columns, receive light reflected on the disk 19 and passed through the optical path switching means 27 and which independently and photoelectrically convert the light. The four light receiving areas are arranged squarely so that the four areas do not cut the part closer to the center and are apart from each other at a prescribed interval.