A gas-insulated switchgear allowing reduction in layout dimension in a direction of axis lines of circuit breakers and also reduction in layout dimension in a direction orthogonal to the direction of the axis lines of the circuit breakers, thereby allowing reduction in installation area. Between two main buses disposed in parallel, first, second and third circuit breakers are disposed as being aligned so that each axis line is orthogonal to a direction of axis lines of the main buses. A branch line drawn from a portion between the first and second circuit breakers and a branch line drawn from a portion between the second and third circuit breakers are connected to respective cable heads. The centers of the cable heads are configured so as to be positioned on a straight line orthogonal to the direction of the axis lines of the main buses.