In a beam irradiation apparatus in which a movable body holds an object, a mark detection system detects a first mark on the movable body while moving the movable body in a first direction and changing an irradiation position of a measurement beam in the first direction, the mark detection system detects a second mark while moving the movable body in the first direction and changing the irradiation position of the measurement beam in the first direction, a controller controls a position of the movable body in a second direction intersecting the first direction during a time period between the detection of the first mark and the detection of the second mark, and the controller controls the movement of the movable body to adjust a positional relation between the object on the movable body and a processing beam, based on results of the detection of the first and second marks.