Abstract: A thermistor has a sealing portion of glass which seals at least a thermistor element body, first and second electrodes, and ends of the first and second lead wires and an insulating portion which covers portions of the first and second lead wires exposed from the sealing portion. The first and second lead wires are spaced from each other and include respective first portions extending from the aforementioned ends and spaced from each other with a first space, respective second portions spaced from each other with a second space larger than the first space, and respective third portions spaced from each other with a space varying from the first space to the second space, between the first and second portions. The insulating portion covers the first portions of the first and second lead wires together and covers the second and third portions of the first and second lead wires independently for each of the first and second lead wires.