According to an embodiment, a gas insulated electrical equipment includes: a high-voltage conductor to be electrically charged; a hermetically sealed tank to be filled with insulating gas, one or more insulating spacers for dividing the hermetically sealed tank into gas compartments and supporting the high-voltage conductor; and a pressure release device equipped with a mouth of flow channel adapted to allow the inside and the outside of the hermetically sealed tank to communicate with each other so as to release the pressure in the hermetically sealed tank, which maintains the hermetically sealed state in an ordinary condition where the pressure in a gas compartment does not exceed the working pressure but releases the pressure in the hermetically sealed tank in an abnormal condition where the pressure in the gas compartment exceeds the working pressure.