A device for holding a laser diode (LD) and a collimate lens. A laser unit includes an LD supporting section supporting the LD, and a lens supporting section supporting the lens positioned opposite to the LD, A connecting portion connects the lens supporting section to the LD supporting section. An adjustment section for adjusting a relative position between the LD and the lens is provided in association with the LD supporting section. The adjustment section allows the LD supporting section to be movable and position-fixable with respect to the lens supporting section as if the LD supporting section serves as a leverage about the connecting portion functioning as a fulcrum.