Abstract: A method for inspecting a photomask is described. Photomask patterns are transferred onto a wafer, and an abnormal photomask pattern is searched out and coordinates thereof are acquired. A photomask region containing the abnormal photomask pattern is defined, and coordinates thereof are acquired. Next, a shot on the wafer is arbitrarily selected, and coordinates of a wafer region in the shot corresponding to the photomask region are acquired. Further, a position of a possible abnormal wafer pattern in the shot corresponding to the abnormal phoromask pattern is calculated on the basis of coordinates of the abnormal photomask pattern, photomask region, and wafer region. Based on the above coordinates, coordinates of the position of a possible abnormal wafer pattern in the shot corresponding to the abnormal phoromask pattern are acquired. Finally, it is determined whether the abnormal wafer pattern indeed exists at the above position in the shot.