To precisely simply detect displacement and direction thereof from focused state and contribute for improvement of exposure accuracy and the like.

The displacement from optimum focused state is monitored on the occasion of pattern transcription on a wafer 115 in an aligner 110 provided by a focus measuring device 130 for measuring the height position of the wafer surface with diagonal incident illumination with a focus monitor method. The displacement and direction thereof from the focused position are acquired by transferring a pattern on the wafer 115 by use of a mask 113 having a focus monitor pattern with its dimension changed according to the displacement from focus state, acquiring position information by the focus measuring device 130 on the occasion of pattern transferring, and measuring the pattern dimension of the focus monitor pattern projected on the wafer 115 with the measuring device 120 to obtain the displacement and direction thereof from focused position according to the acquired information on the position and the pattern dimension measured.