A laser apparatus calculates a temperature of a temperature increase portion that is raised in temperature by reflection light, and determines and outputs an emergency optical output command with the aim of ensuring that the calculated temperature does not exceed a first predetermined temperature, which is set at a lower temperature than an upper limit heat resistance temperature, and if necessary, controlling the temperature to or below a second predetermined temperature set at a lower temperature than the first predetermined temperature. When the emergency optical output command is to be output, a control unit switches an optical output command output thereby to the emergency optical output command and outputs the emergency optical output command.