PURPOSE: To reduce the manufacturing cost of semiconductor products, and improve the workability of a manufacturing apparatus of the semiconductor products, by a method wherein treatment liquid stored in a storing tank while being circulated and filtrated is sucked with a suction pump, filtrated with a first filter, and supplied to the surface of a specimen.

CONSTITUTION: Prior to the coating or treatment liquid L, the treatment liquid L stored in a storing tank 11 is circulated with a circulation pump 17, while previously being filtrated with a second filter 18. When the treatment liquid L is applied to the surface of a specimen S, the treatment liquid L which is stored in the storing tank 11 while being circulated and filtrated in the process is sucked with a suction pump 3 and filtrated with a first filter 14. Then the treatment liquid L is dripped on the surface of the specimen S from a nozzle 15. After that, a spin chuck 52 which fixes the specimen S by vacuum suction is rotated, and the surface of the specimen S is spin-coated with the treatment liquid L. This process may be performed by dripping the treatment liquid L on the surface of the rotated specimen S.