PROBLEM TO BE SOLVED: To provide a laser therapy apparatus 50 capable of executing both of the detection of hardness and laser therapy in a short time, and a laser output control method.SOLUTION: The laser therapy apparatus is equipped with a gas jet control part 54b for jetting gas through a hollow waveguide 60, a detection part 55 and a signal processing part 53 both of which detect the hardness of a treated region E, a laser oscillation part 57 for irradiating the treated region E with a treatment laser beam 57a, a memory part 54c for storing control data 70 showing the output control information on the treatment laser beam 57a by the state of the treated region E discriminated from the information on the hardness and a laser output control part 54a for executing the output control of the laser oscillation part 57 on the basis of the information on the hardness acquired from the detection part 55 and the signal processing part 53 and the control data 70.
