The present invention relates to a laser processing method and the like which use no wavelength conversion technique by nonlinear optical crystals when selectively removing an insulating layer of a printed board, while employing only one wavelength throughout the entire removal processing. A laser processing apparatus (1), preferably used in the laser processing method, has a MOPA structure and comprises a seed light source (100), a YbDF (110), a bandpass filter (120), a YbDF (130), a bandpass filter (140), a YbDF (150), a YbDF (160), and so forth. The laser processing method according to the present invention is a laser processing method of removing an insulating layer comprised of a resin laminated on a conductor layer by irradiating it with pulsed laser light outputted from the laser processing apparatus (1) and uses laser light having a wavelength at which the light absorbed by the conductor layer is less than 10%, and sets the fluence per one pulse to a fracture damage threshold of the insulating layer or higher.