A gas-insulated switchgear includes a grounded tank filled with insulation gas, a center conductor which is disposed in the grounded tank and to which a voltage is applied, an insulating support member which insulates and supports the center conductor, and a nonlinear resistive part disposed at least on a vertically lower side inner surface of the grounded tank and formed by an insulation material containing a nonlinear resistive material. If an electric field applied to the nonlinear resistive part is higher than an electric field value in a vicinity of a contact point between the nonlinear resistive part and a metallic foreign substance mixed in the grounded tank during an operation, a resistivity of the nonlinear resistive part at the center conductor side is lower than a resistivity at which a discharge delay time is equal to an electric field relaxation time constant.