To provide a refrigeration unit capable of adjusting an operation condition of a compression refrigerator in accordance with cooling load and a condition of absorption refrigeration effect and performing economical and efficient operation.

This refrigeration unit used in a cogeneration system is constituted by combining an absorption refrigerator having an evaporator E providing refrigeration effect using exhaust heat as a heat source, a compressor Mc, a first condenser Cc1 cooling by outside air or cooling water, and the compression refrigerator having a first condenser Cc2 connected with the evaporator E of the absorption refrigerator and heat exchange relation and an evaporator Ec providing refrigeration effect. Electric power for operating the compressor Mc is electricity before it is converted into commercial frequency and electricity generated by a generator or electricity which is not converted into commercial frequency. The refrigeration unit may be provided with a control means for operating the compressor when load for the evaporator Ec cannot be covered with refrigeration effect of the absorption refrigerator.