A power conversion apparatus includes a rectifier to convert AC power into constant-current DC power, a resonant inverter to convert the DC power into AC power to be output to a load, and a control unit to receive settings of an output current value of the inverter, a current-supplying time of the inverter, an operation rate defined by dividing the current-supplying time by a sum of the current-supplying time and a non-current-supplying time, and a resonance frequency of the load. The control unit operates the rectifier and the inverter only when it determines that it is operable to perform an output in accordance with the set conditions, based on data in which the output frequency, the current-supplying time and the operation rate are associated with an allowable output current value of the inverter at a temperature equal to or lower than a maximum operable temperature of a switching device.