PURPOSE: To clean a wafer without occurrence of spot-like foreign materials and manufacture a highly reliable semiconductor device with high yield by a method wherein an exhaust pipe having a large diameter is placed on the bottom of a cleaning tank and an alcohol supply pipe is placed in the vicinity of the bottom respectively while pure water is discharged to be replaced with alcohol in a short time.

CONSTITUTION: First a water supply valve 2 is opened to supply pure water to a cleaning tank 1 until the water overflows from the upper end into an exhaust tank 1a. Then a transfer basket 4 with a wafer 5 mounted is immersed and cleaned with water. After the specific resistance being 16MΩ.cm or larger (20°C) is secured, the water supply valve 2 is closed and a drain valve 7 is opened to exhaust the pure water in the cleaning tank 1 immediately. As soon as drain of the pure water is completed, a supply valve 8 is opened to supply isopropyl alcohol solution. The speed for supplying isopropyl alcohol is specified so that it takes approximately 10 seconds for the solution to reach the upper part of the wafer 5. After the isopropyl alcohol solution completely having filled the cleaning tank 1 is assured, the transfer basket 4 is taken out. This method leaves no water drops on the surface of the wafer 5 and eliminates occurrence of spot-like foreign materials even through it takes time until the wafer is dried.