A laser apparatus for operations comprises a power case containing a power supply, etc., a laser tube container head located over the power case, means for supporting the laser tube container head so as to permit rotation in a horizontal plane and in a manner to enable seesaw motion in a vertical plane, a longitudinally telescoping light guide tube attached longitudinally to the laser tube container head, mirror joints connected with the light guide tube, and a manipulator connected detachably with the mirror joints.A forced-oil cooled laser apparatus comprises mirror holder electrodes which hold an inner glass tube and an outer transparent pipe coaxially in an airtight manner, and an intermediate electrode, the mirror holder electrodes being provided with discharge gas intake and outlet ports and with cooling oil intake and outlet ports, the discharge gas intake and outlet ports being connected with a vacuum pump and a discharge gas cylinder, the cooling oil intake and outlet ports being connected with a cooler and a compressor.