A method for correcting a position error of a lithography apparatus comprises inputting position data of exposure pattern, irradiating laser light onto a position reference mask from a position measurement laser system, calculating actual position data of the laser light irradiated onto the position reference mask, and comparing the position data of the exposure pattern with the actual position data of the laser light irradiated onto the position reference mask. With this method, circuit patterns can be accurately formed at predetermined positions on a photomask, and the circuit patterns on the photomask can be accurately formed at predetermined positions on a wafer.