An optical head device for use in a disc player comprises a movable optical assembly in which an objective lens, first and second mirrors, and a light beam generating and detecting unit are supported in common by a supporting member, and a driving mechanism for moving the movable optical assembly in both a first direction along an optical axis of the objective lens and a second direction perpendicular to the first direction, wherein, in the movable optical assembly, a light beam generated in the light beam generating and detecting unit is reflected twice by the first and second mirrors to be changed in its traveling direction, and focused by the objective lens at a position on the optical axis of the objective lens, and a light beam coming from the outside of the movable optical assembly is received by the objective lens to pass therethrough to the second mirror, reflected twice by the second and first mirrors to be changed in its traveling direction, and guided to a photodetector contained in the light beam generating and detecting unit.