Abstract: A level F.sub.A at a shot center of a specified shot is measured. A level F.sub.B is measured at a nonexposure region. A level difference .DELTA.F is calculated based on the level F.sub.A at the shot center and the level F.sub.B at the nonexposure region. After the level difference .DELTA.F is calculated for all the specified shots, an average value .DELTA.F.sub.ave of level differences .DELTA.F is calculated. Thereafter, focusing based on the average value .DELTA.F.sub.ave and subsequent exposure are executed for the respective shots in a step-and-repeat manner. Thereby, a focusing method in photolithography enables formation of elements having good pattern configuration even if the pattern is miniaturized to a higher extent in accordance with high integration.