An integrated sensor chip combining a heater for temperature control and a diode for temperature monitoring was fabricated and its characteristics evaluated. Furthermore, a new packaging structure with a gas permeable film and sensor chip attached to the glass to improve the heat efficiency were developed. Using this packaging structure, the optimum working conditions and protection for the sensor chip were realized. The features of the diode were sufficient to verify the sensor temperature. In terms of the value of heat efficiency per power consumption, we succeeded in advancing its values by about 15% compared to the glassless type. Furthermore, the time response curves for the sensor temperature and power consumption of the heater were measured. The thermal control system consists of a heater and the diode was successfully utilized to maintain the intended temperature. The heat efficiency was improved by attaching a glass and this system was found to be useful for the PPG-FET type hydrogen sensor.