To provide a protection element capable of suitably protecting a protected unit used under a direct current against an overcurrent by eliminating migration of a low melting point alloy.

The protection element has a pair of pin electrodes 1, 1 and a guide shaft 6 is arranged along these pin electrodes 1, 1, and an overcurrent heat-generating piece 2 to be heated by conduction of the overcurrent is arranged striding over the pair of the pin electrodes 1, 1 in a state of being inserted through the guide shaft 80a, and a gap between each of the pin electrodes 1, 1 and the overcurrent heat-generating pieces 2 and a gap between the guide shaft 6 and the overcurrent heat-generating piece 2 are jointed by the low melting point alloy 3, and a compression reaction force of a spring is set so that a lowest position of a first amplitude of a vibration at a spring top end generated by a release of a spring stress energy based on the compression reaction force by melting of the low melting point welding material may be at a height within 0.8h in a direction from a top end of the guide shaft to the pin electrodes, when h is a distance between the pin electrode top end and a case inner face of the guide shaft top end side.