PURPOSE: To obtain a solid laser device small and inexpensive and having high output by cooling a semiconductor laser bar having a plurality of light-emitting points at high efficiency to obtain high output.

CONSTITUTION: An insulating liquid refrigerant is made to flow through a laser bar unit so as to directly come in contact with the laser bar to remove heat from a laser element body or its neighborhood thus allowing highly efficient cooling. For the refrigerant, for instance, carbon fluoride is used.