Disclosed are a valve for a gas circuit breaker, and a gas circuit breaker having the same. The gas circuit breaker comprises a cylinder constituting appearance of the gas circuit breaker, and providing a gas flow path therein, a partition plate having passing holes, and configured to partition inside of the cylinder, a sleeve concentrically disposed in the cylinder, a valve body inserted into the sleeve, and mounted below the partition plate so as to perform a reciprocation along the sleeve, an elastic means configured to upwardly apply an elastic force on a bottom surface of the valve body, and a blocking plate inserted into the sleeve, and mounted between the valve body and the partition plate so as to be moveable in upper and lower directions, wherein the valve body is provided with discharge openings, and the discharge openings are open and closed by movements of the blocking plate.