The present invention is for providing optical head apparatus that can control scatter occurring at locations along the length of the optical path, when laser beam is transmitted through prism constituting the No. 1 prism structural member and the No. 2 prism structural member joined through partially reflecting face. Optical head apparatus 1 performs information recording, information regeneration on an optical recording medium, e.g. DVD; laser beam emitted from laser beam-emitting element is transmitted through a prism. The prism has the structure wherein triangular the No. 1 prism structural member and similarly a triangular No. 2 prism structural member are joined through partially reflecting face.