To effectively transfer heat generated from a resistor to a fusible alloy and to certainly fuse the fusible alloy in a short time, in a protective element having the fusible alloy on one surface of an insulating substrate and resistor on the other surface.

In this protective element, first electrodes 2, 3 are provided on one surface of an insulating substrate 1, an insulating substrate 4 is integrally fixed so as to expose the inner ends of these first electrodes 2, 3, a fusible alloy 5 is connected and fixed across the inner ends of the first electrodes 2, 3, the fusible alloy 5 is coated with a flux 6 and is coated and sealed with an insulator 9, second electrodes 10, 11 are provided on the other surface of the insulating substrate 1, a resistor 12 is connected and fixed across these second electrodes 10, 11, this resistor 12 is coated with an insulator 15, and thermal conductivity of the insulating substrate 1 is set larger than that of the insulator 15.