PURPOSE: To use a condenser effectively for surgical operations by combining condenser lenses which correspond to plural laser beams into one condenser lens body and converging all beams to the same point.

CONSTITUTION: The laser beams of, for example, CO2, Ar, and YAG are transmitted through optical fibers 1, 2, and 3 and projected from their projection ends 1a, 2a, and 3a respectively. The condenser lenses 4, 5, and 6 having incidence surfaces 4a, 5a, and 6a facing those projection ends are combined together to form one condenser lens body. This condenser lens body A converges the beams projected from the condenser lenses 4, 5, and 6 to the same focal point F. Consequently, the respective laser beams are converged to the same focal point and this device is used effectively for surgical operations, etc.