An electronics device includes a power semiconductor device including a temperature detection diode, a first semiconductor integrated circuit device including a detection circuit for detecting VF from the temperature detection diode and a second semiconductor integrated circuit device. The second semiconductor integrated circuit device includes, an outside air temperature acquisition unit which acquires outside air temperature information, a storage which stores temperature characteristic data of the temperature detection diode and a first value based on a signal from the detection circuit at a first temperature and a temperature arithmetic processing unit which calculates a temperature of the power semiconductor device from a third value based on a signal from the detection circuit, the temperature characteristic data, the first temperature acquired by the outside air temperature acquisition unit and the first value.