A laser treatment apparatus for irradiating a laser beam to a patient's eye, comprises: a plurality of laser sources which emit treatment laser beams having different wavelengths, each laser source being held in a main body to be mountable and demountable and connected to a power source through a connector; a light delivery optical system having a mirror for making the laser beams from the laser sources coaxial with each other to deliver each laser beam to the patient's eye; an input unit for inputting mounting information of each laser source; a control unit which checks a predetermined operation of each laser source by a sensor at the time of activation to determine whether an abnormality is present or not in each laser source, and displays an indication that the abnormality is present on a display, wherein the control unit will not perform the operation check whether the abnormality is present or not in the laser source or laser sources unmounted in the main body, based on the mounting information input by the input unit.