Method for identifying leaks in a refrigeration circuit of a compression refrigerating machine, wherein the refrigeration circuit comprises at least an evaporator, a compressor, a condenser, a pressure-reducing valve and an internal heat exchanger, which are interconnected by means of lines, wherein a refrigerant is conducted in the lines, wherein the internal heat exchanger is arranged between the evaporator and the compressor and between the condenser and the pressure-reducing valve, wherein - there are defined, at least in the region of the internal heat exchanger: a) a first measurement point in the line from the internal heat exchanger to the pressure-reducing valve, b) a second measurement point in the line from the evaporator to the internal heat exchanger, c) a third measurement point in the line from the condenser to the internal heat exchanger and d) a fourth measurement point in the line from the internal heat exchanger to the compressor for at least one thermodynamic state variable of the refrigerant for the purposes of determining the temperature of the refrigerant, - the temperature is either measured directly or acquired indirectly by measuring the pressure in conjunction with a physical characteristic of the refrigerant, - the refrigerant temperature determined at the first measurement point is subtracted from the temperature determined at the third measurement point, and a first value is established therefrom, - the refrigerant temperature determined at the second measurement point is subtracted from the temperature determined at the fourth measurement point, and a second value is established therefrom, - a ratio between the first value and the second value is established, - a third value created therefrom is compared with a reference and - a leak is identified if the third value deviates from the reference. - there are defined, at least in the region of the internal heat exchanger: a) a first measurement point in the line from the internal heat exchanger to the pressure-reducing valve, b) a second measurement point in the line from the evaporator to the internal heat exchanger, c) a third measurement point in the line from the condenser to the internal heat exchanger and d) a fourth measurement point in the line from the internal heat exchanger to the compressor for at least one thermodynamic state variable of the refrigerant for the purposes of determining the temperature of the refrigerant, a) a first measurement point in the line from the internal heat exchanger to the pressure-reducing valve, b) a second measurement point in the line from the evaporator to the internal heat exchanger, c) a third measurement point in the line from the condenser to the internal heat exchanger and d) a fourth measurement point in the line from the internal heat exchanger to the compressor - the temperature is either measured directly or acquired indirectly by measuring the pressure in conjunction with a physical characteristic of the refrigerant, - the refrigerant temperature determined at the first measurement point is subtracted from the temperature determined at the third measurement point, and a first value is established therefrom, - the refrigerant temperature determined at the second measurement point is subtracted from the temperature determined at the fourth measurement point, and a second value is established therefrom, - a ratio between the first value and the second value is established, - a third value created therefrom is compared with a reference and - a leak is identified if the third value deviates from the reference.