PURPOSE: To simultaneously seal a plurality of thermistor elements automatically by a method wherein a plurality of conductor patterns are formed on an element-mounted substrate, thermistor patterns are mounted on the conductor pattern, and the thermistor patterns are protected by a protective material by sealing.

CONSTITUTION: A plurality of conductor patterns 31 and 31', on which thermistor elements 44 are to be mounted, are simultaneously formed on the main surface of an element mounting substrate 30 with prescribed regularity, and the thermistor elements 44 are mounted on the conductor patterns 31 and 31' successively, mounted by soldering and connected electrically with the conductor patterns 31 and 31'. Then, the thermistor elements 44 which are mounted on the conductor patterns 31 and 31', are successively sealed by protective glass material 51 in accordance with the conductor patterns 31 and 31'. As a result, the above- mentioned process can be conducted automatically, and the plurality of thermistor elements 44 can be protected by sealing simultaneously.