The invention relates to a gas-insulated switchgear, particularly a gas-insulated medium-voltage switchgear, according to claim 1. In order to satisfy additional safety requirements also with position 2 and 3 disconnectors in gas-insulated switchgears, an inspection glass (9) is inserted/mounted in the housing (10) such that the positions of the switching contact elements can be seen directly or indirectly via optical means from outside the housing.