Abstract: The position of a movable stage is detected without increasing cost or the size of apparatus. An apparatus comprises movable stages (WST, MST) that move along a plane of motion (12a); and a position-detection apparatus that detects the positions of the movable stages (WST, MST) with beams (B1 to B3). The apparatus further comprises driving apparatuses (82, 84) that drives the movable stages (WST, MST); follow-up optical members (30 to 33) which are provided on the driving apparatuses (81, 84) and cause the beams (B1 to B3) to follow the movable stages (WST, MST) as the movable stages (WST, MST) move; and first optical members (34 to 39) which are provided on the movable stages (WST, MST) and are optically coupled with the follow-up optical members (30 to 33).