PURPOSE: To provide the two-beam optical head for optical information recording/reproducing device provided with a separating means which efficiently separates two reflected beams for reproducing and recording without using two semiconductor lasers different by wavelength neither a wavelength separating prism and has a simple and inexpensive optical system.

CONSTITUTION: In the two-beam optical head for optical information recording/ reproducing device, a prism 7 provided with the slope which totally reflects a first reflected beam and refracts a second reflected beam is used as the separating means which separates the first reflected beam from a first spot formed on an optical disk medium 5 and the second reflected beam from a second spot.