PURPOSE: To cut off the supply of overcurrent by ensuring the rupture of an insulation base plate in a short time, upon the start of the overcurrent flow, without any need of setting the resistance value of a heat generating resistance body at an extremely high level, and making the base plate itself extremely breakable.

CONSTITUTION: This fuse resistor 2 is constituted in such a way that an insulation substrate 4 is provided, and the first and second heat generating resistance bodies 10 and 12 are formed on the first plane 8 thereof. Furthermore, constitution is so made that when overcurrent flows across both resistance bodies 10 and 12, the base plate 4, ruptures due to the occurrence of thermal strain caused by the heat generating action of the bodies 10 and 12, thereby cutting both bodies 10 and 12 for the interruption of the overcurrent flow. In this case, the first spring member 6 is provided to energize the base board 4 in a direction to facilitate the rupture thereof.