To prevent the penetration of water to the inside from a place near the operation lever of an earth leakage breaker, and allow no hindrance on the operation of the earth leakage breaker.

The operation lever 8 of an earth leakage breaker 5 installed in an electric box 4 sticks outward from an opening 7, and a waterproof cover 10 made of a rubber-like elastic body entirely covers the operation lever 8 and the opening 7 as keeping a small gap from the whole displacement range of the operation lever 8. The flange portion 11 of the waterproof cover 10 is pressure-contacted by the inner surface of the electric box 4 so that the inside and the opening 7 of the electric box 4 is sealed by the waterproof cover 10.