A semiconductor laser light source comprising: a semiconductor laser array in which a plurality of semiconductor lasers (2b1, 2b2) are provided and stripes of the plurality of semiconductor lasers are arrayed at equal intervals in a stripe width direction; and a heat sink having a first surface on which the semiconductor laser array is mounted, and a second surface opposite to the first surface and in contact with a cooling unit , wherein the semiconductor laser array comprises a first semiconductor laser group (2b1) in a central side in the stripe width direction and a second semiconductor laser group (2b2) on both end sides, wherein the first semiconductor laser group (2b1) is in contact with a first region in the first surface, and a second region in the second surface is opposite to the first region in the first surface, wherein both the first region and the second regions correspond to a first portion (3b1) of the heat sink, and each of the second semiconductor laser groups (2b2) is in contact with a third region of the first surface and a fourth region in the second surface is opposite to the third region in the first surface, wherein both the third region and the fourth region correspond to a second portion (3b2) of the heat sink, wherein an area per semiconductor laser of the second region, in the first portion (3b1) of the heat sink, is smaller than an area per semiconductor laser of the fourth region, wherein, in the second portion (3b2) of the heat sink, the area of the fourth region per semiconductor laser is gradually increased from the central side to both end sides in the stripe width direction. a semiconductor laser array in which a plurality of semiconductor lasers (2b1, 2b2) are provided and stripes of the plurality of semiconductor lasers are arrayed at equal intervals in a stripe width direction; and a heat sink having a first surface on which the semiconductor laser array is mounted, and a second surface opposite to the first surface and in contact with a cooling unit , wherein the semiconductor laser array comprises a first semiconductor laser group (2b1) in a central side in the stripe width direction and a second semiconductor laser group (2b2) on both end sides, wherein the first semiconductor laser group (2b1) is in contact with a first region in the first surface, and a second region in the second surface is opposite to the first region in the first surface, wherein both the first region and the second regions correspond to a first portion (3b1) of the heat sink, and each of the second semiconductor laser groups (2b2) is in contact with a third region of the first surface and a fourth region in the second surface is opposite to the third region in the first surface, wherein both the third region and the fourth region correspond to a second portion (3b2) of the heat sink, wherein an area per semiconductor laser of the second region, in the first portion (3b1) of the heat sink, is smaller than an area per semiconductor laser of the fourth region, wherein, in the second portion (3b2) of the heat sink, the area of the fourth region per semiconductor laser is gradually increased from the central side to both end sides in the stripe width direction. <EOS>