The invention provides coating units, heat-treating units, and a first main transport mechanism for transporting substrates to each of these treating units. The substrates are transferred from the first main transport mechanism to a second main transport mechanism through a receiver. When a substrate cannot be placed on the receiver, this substrate is placed on a buffer. Thus, the first main transport mechanism can continue transporting other substrates. The other substrates in the treating units are transported between the treating units without delay, to receive a series of treatments including coating treatment and heat treatment as scheduled. This prevents lowering of the quality of treatment for forming film on the substrates.