A gas insulated switchgear includes: a gas-tight housing; at least one shaft extending through an opening in the gas-tight housing, which shaft is partially rotatable and/or translatable; a sealing means arranged in the opening for sealing the shaft relative to the gas-tight housing, the sealing means including a sealing bellows having a first mounting rim on one axial end, a second mounting rim on an other axial end, and a bellow body in between the first and second mounting rims; and a mounting ring mounted coaxially to the shaft. The sealing bellows is arranged around the shaft, with the first mounting rim to the housing and with the second mounting rim to the mounting ring.