To provide a small-sized leak relay equipment, by constituting a leak detection means which detects leak on the basis of current unbalance in a load circuit and outputs a detection signal, by using magnetoelectric transducers.

A first Hall element 9 and a second Hall element 10 are used as magnetoelectric transducers, and set so as to detect magnetic flux change due to current unbalance. A first permanent magnet 12 and a second permanent magnet 13 are so installed that the mutual positional relation to the first and the second Hall elements are changeable. When current unbalance due to leak is generated in a load circuit, the first and the second Hall elements 9, 10 output a leak detection signal. An amplifier 11 amplifies the leak detection signal, input it in the gate of an SCR 7 via a thyristor driver 8, makes a current flow in a leak relay 6, turns normally closed contact parts 6a, 6b of the relay 6 off, and breaks the load circuit 30. Thereby a leak relay equipment can be miniaturized.