A high precision printing method taking into consideration the variance in the thickness of a printing target. An ink-jet printing method comprises the steps: measuring a distance between a printing target and at least one nozzle; measuring a flying speed and a flying angle of ink discharged from the at least one nozzle; printing a test substrate with ink to identify a location on which ink is spotted, and calculating a thickness-related displacement that is a displacement from the location on which the ink is spotted, based on a thickness difference between the printing target and the test substrate from results, and the flying speed and the flying angle of the ink; and discharging ink from the at least one nozzle to achieve actual printing of the printing target with the ink while correcting the thickness-related displacement.