A laser apparatus (100) has a semiconductor laser device (12a to 12c),
coolant jetting means (24), and a heatsink (18a to 18c). The
semiconductor laser device has a light output surface (50) for emitting
laser light. The coolant jetting means has a coolant chamber (53) for
accommodating a coolant, an inflow port (54) communicating with the
coolant chamber, and a jet port (25) opposing the light output surface of
the laser device. The heatsink has a laser mount surface (36) for
mounting the semiconductor laser device, and a flow path (68a to 68c)
where the coolant (56) jetted from the jet port flows in. When the
coolant chamber is fed with the coolant, the jet port jets the coolant
onto the light output surface of the semiconductor laser device. Since
the light output surface is directly cooled by a jet flow of the coolant,
cooling efficiency is excellent.