Patent ID: 8401047

Claim:
A semiconductor laser device comprising: a housing; a heatsink having a cooling medium passage therein, the heatsink disposed in the housing; a laser output section directly or indirectly fixed to the heatsink; and a planar member disposed outside a wall surface of wall surfaces forming the housing, wherein, the housing has a first through-hole and a second through-hole in the wall surface facing the planar member, a first passage-forming member having a passage for feeding a cooling medium to the cooling medium passage of the heatsink is disposed inside the first through-hole, a second passage-forming member having a passage for discharging the cooling medium from the cooling medium passage of the heatsink is disposed inside the second through-hole, a third through-hole for feeding the cooling medium to the cooling medium passage of the heatsink is formed in the planar member at a position that meets with the first passage-forming member, and a fourth through-hole for discharging the cooling medium from the cooling medium passage of the heatsink is formed in the planar member at a position that meets with the second passage-forming member.