In a substrate processing apparatus receiving substrates held in a common carrier in a horizontal attitude, the substrates are transferred in the horizontal attitude from the common carrier to an exclusive carrier. The exclusive carrier is rotatable on a horizontal axis. By rotating the exclusive carrier, the substrates are turned from the horizontal attitude to a vertical attitude. Then, the substrates held in the vertical attitude are taken out of the exclusive carrier and transferred to a processing part for processing in the vertical attitude. This allows a simple and speedy turn of the plurality of substrates. Further, even the apparatus for processing the substrates in a vertical attitude can transfer the substrates into and out of the apparatus in the horizontal attitude by using the common carrier.