A bearing grease contains a base oil and a thickener. The base oil is a base oil mixture containing a polyalphaolefin and an ester. The bearing grease is used in an atmosphere of a fluorine compound refrigerant containing no hydrogen. A bearing using the bearing grease does not cause elution of grease for a long time. Further, since there is no need for a collecting system unlike lubricating oil, the arrangement around the bearing can be made compact. Thus, the bearing can be easily applied in a form of an energy recovery equipment to a vehicle or various industrial machineries.