A plurality of heads configuring an encoder system is arranged on a wafer table, and positional information of a wafer table in the XY plane is measured, based on an output of a head opposed to a scale plate (diffraction grating). And, a relative position (including relative attitude and rotation) of each head with the wafer table is measured herein by a measurement system arranged inside the head. Accordingly, by correcting the positional information based on the information of the relative position which has been measured, a highly precise measurement of the positional information of the wafer table becomes possible even in the case when the position (attitude, rotation) of the head changes with the movement of the wafer table.