The object of the present invention is to provide: high-reliability and long-life CO.sub.2 refrigerant compressor-use bearings that uses bearing materials high in wear resistance and in baking resistance, and; such a compressor, air conditioner, refrigerator, and hot-water supply machine that each employ these bearings.The CO.sub.2 refrigerant compressor-use bearings according to the present invention, and the compressor, air conditioner, refrigerator, and hot-water supply machine that employ these bearings, wherein the bearings are characterized in that each bearing comprises a cylindrically shaped member whose graphite-containing carbonaceous base material has pores impregnated with tin or with one type of metal selected from the IB group or the VIII group, except iron, or with an alloy based on these metals, and in that each bearing satisfies at least one of the requirements that the bearing should comprise a carbonaceous base material containing 20 to 50 weight percent graphite, that the Shore hardness of the corresponding member should range from 65 to 120, that the compressive strength of the corresponding member should range from 200 to 500 MPa, that the porosity rate of the corresponding member should range from 0.05 to 2.00 volume percent, and that the metal or alloy contained in the corresponding member should contain at least either vanadium or titanium or both at the rate of 0.2 weight percent or less.