More specifically, each of the holding plates 211 has, as shown in FIG. 6A, a vacuum chuck VP for holding a substrate W from underneath by vacuum suction. After sliding under each of the substrates W through the backward opening part Ea2 of the common carrier SC, the holding plates 211 moves upward to hold the substrates W by vacuum suction. The substrate transfer robot 21 then moves in a X direction as shown in FIG. 5B so that the substrates W are transferred through the forward opening part Ea1 of the common carrier SC and Eb1 of the exclusive carrier EC into the exclusive carrier EC, where the substrates W are placed on the racks Nb by moving down the holding plates 211 to release the substrates W. After the transfer of the substrates W, the substrate transfer robot 21 moves in the negative X direction as shown in FIG. 5C.