An electrical apparatus, which is immovable in a facility, comprises plural electric circuits. Each electric circuit has one or more resistance elements and is connected to each input terminal connected a power source. The electric circuits are arranged positionally closely with each other. In each electric circuit, a desired functional circuit is connected in series to the resistance element, and a protection circuit is connected in series to the resistance element and connected in parallel with the functional circuit. A discharge member is provided in each electric circuit and arranged between each input terminal and the functional circuit. The discharge member includes a discharge gap which allows the discharge member to face with the discharge member of an adjacently arranged electric circuit.The discharge gap discharge deliberately to the adjacently positioned discharge member when a voltage applied to a selected electric circuit exceeds a predetermined voltage value.