An attitude of a measurement reference surface of a positioning master is adjusted using an auto-collimator, the positioning master being disposed so that the adjusted measurement reference surface is located on a designed position, and the light beam irradiated from the measurement reference surface is detected by a CCD camera to set the reference position. A calibrated position relative to the designed position is set based on average optical characteristics obtained by a projection lens inspection apparatus as an initializing process and the CCD camera is moved to the calibrated position. An optical device is mounted and a position of a liquid crystal panel is adjusted while detecting the light beam irradiated from the light-irradiating surface of a cross dichroic prism of the optical device by the CCD camera and the liquid crystal panel is fixed with ultraviolet curing adhesive.