Gas Breaker

There is provided a gas circuit breaker that includes: a puffer shaft connected to one of a pair of arcing contacts, a puffer cylinder that is coaxially provided on an outer circumference of the puffer shaft, an insulating nozzle that is fixed to the puffer cylinder on a breaker side, an insulating rod that connects the puffer shaft and an operating device to each other, a shaft guide that is provided on an outer circumference of the puffer shaft and the insulating rod, and an exhaust guide that is provided on an outer circumference of the shaft guide, in which hot gas is discharged into a gas tank through a shaft exhaust hole of the puffer shaft, between the puffer shaft and the shaft guide, and a conductor exhaust hole of a movable side exhaust conductor in the middle of interrupting operation, the shaft exhaust hole of the puffer shaft communicates with a shaft guide exhaust hole of the shaft guide in a region near a current zero point before the termination of the interrupting operation, and thus an exhaust flow path changes.