To calculate a synchronous error reflecting the synchronous accuracy of actual exposure, by storing the actual speeds of a reticle stage and a wafer stage and a speed error due to the inclination of a wafer stage.

A reticle stage actual shifting speed is calculated from a reticle stage position detected by an interferometer 33X, a wafer stage actual shifting speed is calculated from a wafer stage position detected by an interferometer 34X, and an inclination angle to the optical axis of the wafer stage is measured. Then, a sign error dependent on the inclination angle is calculated and a speed error is calculated in response to the sign error. The reticle actual shifting speed becomes the target value, the wafer shifting speed is controlled to be a speed obtained by correcting the target value with the speed error, and a wafer is exposed. The reticle shifting speed, wafer shifting speed and the speed error are stored by being mutually related, and a synchronous error is calculated by reducing the speed error from the difference between the reticle shifting speed and the wafer shifting speed.