In the present chiller apparatus, a refrigerant flow path is branchably attached to a lower electrode serving as a large sample table, which copes with a case where the surface area of a sample is large in a configuration in which a plasma treatment device connected to a refrigerant cycle equipped with a heating device is applied. A control device transmits a heating adjustment control signal generated based on a result of a PID arithmetic operation including proportion, integration, and differentiation on a lower electrode refrigerant pipe refrigerant detection temperature detected from a temperature sensor provided in the vicinity of a refrigerant flow path of a heat insulating portion relative to the lower electrode of a lower electrode refrigerant pipe connected to be linked to the refrigerant cycle to a heating device and performs feedback control such that the lower electrode refrigerant pipe refrigerant detection temperature becomes a setting temperature.