A manifold communicatively connects a plurality of coating processing units with an air conditioning unit. The manifold is formed by branching a common pipe into a plurality of distributing pipes. The air conditioning unit performs temperature control to set air passing through a branch point of the manifold to a temperature slightly lower than a target temperature in processing units. Secondary heaters secondarily heat air passing through joints between the distributing pipes and the processing units to the target temperature thereby supplying accurately temperature-controlled air to processing parts. Air from the air conditioning unit is diverted thereby suppressing the height of the overall apparatus. Thus, a substrate processing apparatus capable of inhibiting the height of the overall apparatus from remarkable increase also when vertically stacking processing parts in multiple stages and supplying temperature-controlled air to the processing parts with sufficient accuracy.