An object is to provide 1-1/2-CB-type gas insulated switchgear with which it is possible to secure convenience during maintenance and inspection processes and to reduce installation space therefor. Each integral unit is structured by arranging partial units (I), (II), and (III) side by side, while line-side devices are configured so as to branch from positions between the partial units positioned adjacent to each other. Each of the partial units (I), (II), and (III) is structured by connecting a current transformer and a disconnector in sequence to each of two branch outlets (i.e., upper and lower branch outlets) that are horizontally drawn out from a lateral face of a vertical-type circuit breaker in the same direction. Any two partial units positioned adjacent to each other are connected together in series by connecting the disconnectors included therein with a connection bus. The line-side devices are positioned so as to oppose the circuit breakers while the disconnectors are interposed therebetween. The switchgear includes a plurality of integral units. Two ends of each of the integral units are respectively connected to two main buses that are provided in an upper position and a lower position while the disconnectors are interposed therebetween.