PURPOSE: To provide a gas insulated switchgear wherein a pressure proof test, when it is performed, can be easyly operated without separating an adjacent equipment from a connection device, to enable a work time to shorten of this pressure proof test.

CONSTITUTION: Gas insulating bus lines 3, 4 of an adjacent equipment are connected to both ends of a connection device 1. An internal conductor 16, electrically connecting conductors 11, 11 of these gas insulating bus lines 3, 4 in a vessel 2 of the connection device 1, is divided into internal conductors 16a, 16b, 16c. A pick finding part, capable of taking out the internal conductors 16a, 16b, 16c, is formed in an upper part of the vessel 2, and this pick finding part is closed with a mountable/demountable cover 2a.