A refrigerating system includes: an evaporator (2) for performing a cooling operation as a refrigerant is evaporated; a compressor (4) for compressing the refrigerant discharged from the evaporator as a mover is reciprocally moved; a condenser (86) for changing the refrigerant compressed in the reciprocating compressor to a liquid refrigerant; and a capillary tube (8) for decompressing the refrigerant discharged from the condenser and transferring it to the evaporator. Hydrocarbon consisting of carbon and hydrogen, a sort of natural refrigerant, is used as the refrigerant, and a paraffin-based lubricant, a sort of a mineral oil, is used as the lubricant, so that a lubricating performance and a performance of the refrigerating system can be improved.