PURPOSE: To provide a sliding mechanism preventing the gap between a ceramic member and a metal member from being deviated from a proper range by the temperature change during usage and excellent in abrasion resistance and stability and to provide a refrigerant compressor having the improved abrasion resistance of a slide section under severe operating conditions.

CONSTITUTION: A sliding mechanism is constituted of a metal member and a ceramic member slid together, and a low-expansion metal material having the expansion coefficient of about 10×10-6/1°C is used for the metal member. A refrigerant compressor is provided with a compression mechanism 5 arranged in a sealed container 1 and motor mechanism 4 connected to the compression mechanism 5 via a shaft 6, and the sliding mechanism is used for slide sections of the compression mechanism 5 (e.g. slide sections between vanes and a cylinder 9) and slide sections of the shaft 6 (e.g. slide sections between the shaft 6 and bearings 7, 8).