Abstract: The present invention is for the purpose of providing a medical laser irradiation apparatus which applies laser beams of two or more wavelengths, incapable of transmitting in a quartz optical fiber, through the use of an optical fiber cable, with this medical laser irradiation apparatus being easy to handle and producible at a low cost, and also capable of making irradiation through the use of a relay optical fiber cable comprising a quartz optical fiber. For this purpose, this apparatus is composed of a laser irradiation apparatus to output laser beams of a plurality of wavelengths capable of being transmitted by a quartz optical fiber, and two or more kinds of irradiation optical fiber cables including an optical fiber cable having a quartz optical fiber and containing a solid state laser medium and/or a nonlinear optical crystal at its tip portion.