To provide a thermo-protector capable of being mounted similarly to other electronic components by a flow method or a reflow method even if the thermo-protector has operating temperatures lower than soldering temperatures of the flow method or the reflow method, and to provide a conductive heat-sensitive fusible material used as a member of the thermo-protector.

A conductive heat-sensitive material formed by binding semiconductor ceramic particles (a) of which the specific resistance has a positive temperature characteristic, and resistor particles (b) with each other by a binder (c) melting at a predetermined temperature is used as the fusible material. When an ambient temperature rises, the specific resistance value of the semiconductor ceramic particles exponentially increases across a specific temperature lower than a fusion starting point of the binder, as the result, the density of a current flowing through the resistor particles is drastically increased, the conductive heat-sensitive fusible material is heated by the Joule heat generation of the resistor particles, the binder is melted, and the binder liquidized. By setting the melting point or softening point of the binder of the conductive heat-sensitive fusible material higher than the soldering temperatures of the flow method or reflow method, the thermo-protector can be mounted by the flow method or the like without causing a trouble.