When both a wafer transfer means in a first transfer device and a wafer transfer means in a second transfer device move downward at the same time, the amount of exhaust air by an exhaust fan is increased by the control of a control section, whereby the down flow of clean air is intensified. Turbulence of air flow caused when both the wafer transfer means in the first transfer device and the wafer transfer means in the second transfer device move downward at the same time is absorbed by the down flow intensified as described above.

A current member is disposed above a wafer holding section for holding a wafer and a top plate and a bottom plate of the current member are positioned so that respective air holes are overlapped each other in a vertical direction, and a developing solution is heaped on a front face of the wafer. Thereafter, the developing is performed with the bottom plate of the current member slid in a lateral direction so that the air holes are not overlapped each other in the vertical direction. In this configuration, air streams to the wafer are obstructed during the developing because the air holes in the current member are obstructed in the vertical direction, whereby occurrence of temperature distribution of the developing solution within the plane of the wafer caused by flows of air currents to the wafer is prevented and uniform developing processing can be performed.

A blast unit for sending air from the top of a processing chamber to the bottom thereof and an exhaust pipe for exhausting gas from the bottom of the processing chamber are provided. Concomitantly with a change in pressure in the processing chamber, intervals of a slit damper and/or the degree of opening of a damper is controlled by a controller and thus a blast amount or an exhaust amount is controlled, thereby maintaining the pressure in the processing chamber almost constant.

Thermal processing unit sections each with ten tiers and coating processing unit sections each with five tiers are disposed around a first main wafer transfer section and a second main wafer transfer section, and in the thermal processing unit section, the influence of the time required for substrate temperature regulation processing on a drop in throughput can be reduced greatly by transferring the wafer W while the temperature of the wafer W is being regulated by a temperature regulation and transfer device.

An atmospheric conditioning unit for supplying temperature- and humidity-controlled air to a chemical processing part (spin coater) is arranged immediately above a chemical processing part, between this chemical processing part and a heat treatment part (including a hot plate and a cool plate). Namely, the chemical processing part, the atmospheric conditioning unit and the heat treatment part are vertically arranged in a stacked manner. The atmospheric conditioning unit receives external air from an opening. A closed partition is provided to block air flow between the atmospheric conditioning unit and a transport area. The temperature- and humidity-controlled air supplied from the atmospheric conditioning unit to the spin coater forms a downflow in the spin coater, and thereafter rises through an opening and joins with the air flowing from the opening, to be introduced into the atmospheric conditioning unit again and reused.