A refrigerant compressor includes a compression unit having a roller and a vane for compressing refrigerant. The vane has a film having first to fourth layers on its metallic base member. The first layer is made of chromium. The second layer is made of chromium and tungsten-carbide. The third layer is made of metal-containing amorphous-carbon containing at least tungsten or tungsten-carbide. The fourth layer is made of non-metal-containing amorphous-carbon containing carbon and hydrogen. In the second layer, chromium content-rate on a first-layer side is larger than on a third-layer side, and tungsten-carbide content-rate on the third-layer side is larger than on the first-layer side. In the third layer, content-rate of the at least tungsten or tungsten-carbide on a second-layer side is larger than on a fourth-layer side. The roller with which an end-edge of the vane slidably-contacts is made of flake graphite cast iron containing molybdenum, nickel and chromium.