A substrate processing apparatus includes a liquid processing module, including a carry-out/in port of a substrate, in which a first liquid processing device and a second liquid processing device provided at a position farther from the carry-out/in port than the first liquid processing device is are provided; and a transfer device configured to carry the substrate out from and into the liquid processing module. The first liquid processing device performs a first liquid processing on the substrate. The second liquid processing device performs a second liquid processing on the substrate before or after the first liquid processing. The transfer device includes a substrate holder configured to be moved back and forth in a first horizontal direction, and carries the non-processed substrate into the first liquid processing device through the carry-out/in port and carries the processed substrate out from the first liquid processing device through the carry-out/in port.