PURPOSE: To decide the material optimum for a vacuum chamber of a producing equipment for a semiconductor device by analyzing the substance stuck on the surface of a sample or the reactive substance formed on the surface thereof, and investigating the direction for removing the stuck substance or the reactive substance.

CONSTITUTION: Samples 3 are allowed to stand in the four corners of the inside of a vacuum chamber 1 in the vicinity of the stage 2 of a producing equipment for an existing semiconductor device. These samples 3 are treated by surface treatment for evaluating the material to be evaluated. Stainless steel, copper and aluminum, etc., are used as the material. Electrolytic polishing and grinding polishing are adopted as surface treatment. After treatment of this equipment is performed in this state in a plurality of times, these samples 3 are taken out to the outside of the vacuum chamber 1. Evaluation is performed for these taken-out samples in the various evaluation items by using various evaluating methods and the various measuring instruments. A wiping method described below is used as a method for removing the substance stuck on the surfaces of these samples or the reactive substance formed on the surfaces thereof. The wiping method is performed by incorporating alcohol or pure water into commercially available microstar which is used for cleaning of a clean room.