Laser processing apparatus and processing method

The laser processing apparatus 1 includes a processing light source 2 for emitting processing light for processing a tooth 13A or the gingiva 13B, the halogen lamp 3 for emitting illumination light for illuminating the tooth 13A or the gingiva 13B, or teeth 13A includes a detector 4 capable of detecting light of a plurality of wavelengths from the gingival 13B, and a control unit 5 for controlling the first light-emitting state of the light emitting portion 2. Detector 4 has a first detection element 6 having different light receiving sensitivity by the wavelength and the second detection element 7, to detect the light intensity of the different wavelengths, and outputs the detection result to the control section 5 . Control unit 5, based on the ratio of light respective light intensities of different wavelengths detected by the detecting unit 4, and controls the light emitting state of the processing light source 2.