An abnormality determination device configured to determine an abnormality of a compressor of a refrigeration apparatus, the refrigeration apparatus including a refrigerant circuit, and the refrigerant circuit including the compressor, a condenser, and an evaporator and being configured so that a refrigerant circulates through the compressor, the condenser, and the evaporator, the abnormality determination device comprising: a calculator configured to calculate a deviation degree of the compressor from a normal state based on data related to operation of the refrigeration apparatus; and a determination unit configured to determine whether the compressor has an abnormality or to estimate an abnormality occurrence time based on a calculation result of the calculator, wherein the data related to operation of the refrigeration apparatus include data related to operation of the refrigeration apparatus in a first period and data related to operation of the refrigeration apparatus in a second period that differs in length from the first period, the calculator is configured to calculate a first index value from the data related to operation of the refrigeration apparatus in the first period and calculate a second index value from the data related to operation of the refrigeration apparatus in the second period, the calculator is configured to calculate the deviation degree of the compressor from the normal state based on the first index value and the second index value, and the determination unit is configured to determine whether the compressor has an abnormality or estimate an abnormality occurrence time based on the deviation degree of the compressor from the normal state; wherein the data related to operation of the refrigeration apparatus in the first period include data for one day, and characterized in that the data related to operation of the refrigeration apparatus in the second period include data for ten days or more and thirty days or less; wherein the calculator is configured to calculate the first index value from a moving average of the data related to operation of the refrigeration apparatus in the first period, and wherein the calculator is configured to calculate the second index value from a moving average of the data related to operation of the refrigeration apparatus in the second period. a calculator configured to calculate a deviation degree of the compressor from a normal state based on data related to operation of the refrigeration apparatus; and a determination unit configured to determine whether the compressor has an abnormality or to estimate an abnormality occurrence time based on a calculation result of the calculator, wherein the data related to operation of the refrigeration apparatus include data related to operation of the refrigeration apparatus in a first period and data related to operation of the refrigeration apparatus in a second period that differs in length from the first period, the calculator is configured to calculate a first index value from the data related to operation of the refrigeration apparatus in the first period and calculate a second index value from the data related to operation of the refrigeration apparatus in the second period, the calculator is configured to calculate the deviation degree of the compressor from the normal state based on the first index value and the second index value, and the determination unit is configured to determine whether the compressor has an abnormality or estimate an abnormality occurrence time based on the deviation degree of the compressor from the normal state; wherein the data related to operation of the refrigeration apparatus in the first period include data for one day, and characterized in that the data related to operation of the refrigeration apparatus in the second period include data for ten days or more and thirty days or less; wherein the calculator is configured to calculate the first index value from a moving average of the data related to operation of the refrigeration apparatus in the first period, and wherein the calculator is configured to calculate the second index value from a moving average of the data related to operation of the refrigeration apparatus in the second period.