In manufacturing a laser light source module comprising a heat sink whereon a solid-state laser element, an excitation light source, and a wavelength conversion element are mounted, and a stem for supporting the heat sink, the heat sink is divided into three blocks, that is, a first block mounted with a laser oscillating portion for the solid-state laser element on the top face, a second block mounted with the semiconductor laser element for emitting excitation light for the laser oscillating portion and a first temperature sensor on the top face and mounted with a first heater on a predetermined face, and a third block mounted with the wavelength conversion element for wavelength-converting the fundamental wave laser light oscillated by the laser oscillating portion and a second temperature sensor on the top face and mounted with a second heater on a predetermined face. Only the second block is fastened to the stem by the side face or bottom face, the first block is fastened to another side face of the second block, and the third block is fastened to the side face of the first block, reducing the size and improving the positional accuracy of each element.