PURPOSE: To perform a precise operation even when the set temperature of a device is high by forming a resin layer for sealing a case in which a temperature sensitive pellet is received from a resin layer having a glass transition temperature of 250°C or higher or a plurality of layers containing this layer.

CONSTITUTION: An existing temperature fuse is fixed in such a manner that a second lead 6 is on the upside and vertical. A polyparabanic acid dissolved with DMF or NMP is installed to a case 1 which is the surface and peripheral part of a sealing resin layer 12 and the lead 6 followed by drying. Its hardening temperature is lower than the melting temperature of a temperature sensitive pellet 4. Since the situation where a sealing resin layer 15 is melted prior to the pellet is never caused when the pellet is melted at temperature lower than 250°C, the current can be cutoff precisely at a set temperature.