Recently, studies using a thermal imaging camera for precise diagnosis and monitoring of the status has been conducting actively. Furthermore, application of monitoring device for conditions monitoring has been increasing. This study was carried out using the temperature sensor and thermal imaging camera in order to measure out the temperature of the contactor and relay on the switchboard of KTX passenger car. The temperature distribution of contactor was more higher than the relay relatively. However, it was found that it is satisfied with the H-types which is a rating for insulation proposed by manufacturer. In the measurement using the temperature sensor, the temperature was maximum of 58℃, In case of the measurement using the thermal imaging camera, the temperature was maximum of 89℃. Therefore, it is determined that the measurement of the coil temperature using a thermal imaging camera is effective.