A gas delivery system including: a feeder for feeding a gas to a tank; a pressure storage container unit which has a plurality of pressure storage containers, and sends out the gas to the feeder; a gas supply unit; and a controller. The controller implements a storing operation that a specified pressure storage among the plurality of pressure storage containers is supplied with the gas until a pressure of the specified pressure storage container reaches a reference pressure or greater, after finish of a delivery of the gas to one tank carrier, and a sending operation that the gas is sent out from another pressure storage container except the specified pressure storage container to the feeder, and then sent out from the specified pressure storage container to the feeder on a receipt of a shift indication from the feeder, at a delivery of the gas to a subsequent tank carrier.