In a substrate processing apparatus, before a carrier is carried by a carrier arm, a carrier jig is held by a holding part provided to the carrier arm. First, the carrier arm is actuated to move the holding part of the carrier arm to a preset lowering start position. Then, an image including an opening in a table is taken. Thereafter, a distance between a central position of the opening and a central position of a region of the image is calculated, so as to obtain an amount of horizontal positional shift between the preset lowering start position and an ideal position. The lowering start position of the holding part is corrected by the positional shift as a correction value, whereafter the carrier is placed on the table at the corrected lowering start position.