Provided are a heat sink material made of an alloy or a composite material including two or more types of elements which has an end surface that makes possible formation of an edge portion on which at least a laser element is mounted, a manufacturing method for the same, and a semiconductor laser device including the heat sink material. A heat sink material (10) is made of an alloy or a composite material including two or more types of elements, and provided with a main surface having a relatively large area and a secondary surface having a relatively small area which crosses the main surface, and the secondary surface includes a surface on which a discharging process has been carried out using a discharge wire (200) that is placed approximately parallel to the main surface. The manufacturing method for the heat sink material (10) is provided with the steps of placing the discharge wire (200) on a material (100, 50) to be approximately parallel to the main surface, and carrying out the discharging process on the material (100, 50) using the discharge wire (200) placed as described above.