A laser beam profiler unit for measuring an intensity distribution of a laser beam oscillated from a laser oscillator includes a magnifying optical system for magnifying a spot diameter of the laser beam oscillated from the laser oscillator and focused by a condensing lens, a first transmission prism for attenuating the laser beam, a second transmission prism for further attenuating a laser beam reflected by the first transmission prism, an image capturing element for detecting the laser beam reflected by the second transmission prism, and an analyzer for analyzing an intensity distribution of a spot of the laser beam from data of the laser beam detected by the image capturing element.