There is provided a semiconductor laser device including a plurality of members constituting a first group and a second group in each of which a semiconductor laser element is incorporated, a cooling jacket having, on a surface of the cooling jacket, a first region in which the member of the first group is disposed and a second region in which the member of the second group is disposed, and a cooling medium channel which is disposed in a portion close to the first region and separate from the second region inside the cooling jacket and through which a cooling medium passes.