A gas delivery system for delivering a gas to a tank carrier including a tank, comprising: a feeder for feeding the gas to the tank of the tank carrier; a pressure storage container unit which has a plurality of pressure storage containers for storing the gas, and sends out the gas to the feeder, each of the plurality of pressure storage containers being configured to store the gas at a reference pressure (β3) or higher; a gas supply unit for supplying the gas to the pressure storage container unit; a plurality of pressure sensors (41, 42, 43, 44); and a controller for controlling execution of the gas supply unit and the sending of the gas from the pressure storage container unit, wherein the controller implements a storing operation that a specified pressure storage container among the plurality of pressure storage containers is supplied with the gas until a pressure of the specified pressure storage container reaches the reference pressure (β3) or greater, and another pressure storage container which is not the specified pressure storage container is supplied with the gas until a pressure of said another pressure storage container reaches a pressure which is a set pressure (β1) or higher, and lower than the reference pressure (β3) when the pressure of said another pressure storage container is lower than the set pressure (β1), after finish of a delivery of the gas to one tank carrier, and a sending operation that the gas is sent out from said 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 after shifting from the another pressure storage container to the specified pressure storage container on receipt of a shift indication from the feeder, at a delivery of the gas to a subsequent tank carrier. a feeder for feeding the gas to the tank of the tank carrier; a pressure storage container unit which has a plurality of pressure storage containers for storing the gas, and sends out the gas to the feeder, each of the plurality of pressure storage containers being configured to store the gas at a reference pressure (β3) or higher; a gas supply unit for supplying the gas to the pressure storage container unit; a plurality of pressure sensors (41, 42, 43, 44); and a controller for controlling execution of the gas supply unit and the sending of the gas from the pressure storage container unit, wherein the controller implements a storing operation that a specified pressure storage container among the plurality of pressure storage containers is supplied with the gas until a pressure of the specified pressure storage container reaches the reference pressure (β3) or greater, and another pressure storage container which is not the specified pressure storage container is supplied with the gas until a pressure of said another pressure storage container reaches a pressure which is a set pressure (β1) or higher, and lower than the reference pressure (β3) when the pressure of said another pressure storage container is lower than the set pressure (β1), after finish of a delivery of the gas to one tank carrier, and a sending operation that the gas is sent out from said 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 after shifting from the another pressure storage container to the specified pressure storage container on receipt of a shift indication from the feeder, at a delivery of the gas to a subsequent tank carrier. a storing operation that a specified pressure storage container among the plurality of pressure storage containers is supplied with the gas until a pressure of the specified pressure storage container reaches the reference pressure (β3) or greater, and another pressure storage container which is not the specified pressure storage container is supplied with the gas until a pressure of said another pressure storage container reaches a pressure which is a set pressure (β1) or higher, and lower than the reference pressure (β3) when the pressure of said another pressure storage container is lower than the set pressure (β1), after finish of a delivery of the gas to one tank carrier, and a sending operation that the gas is sent out from said 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 after shifting from the another pressure storage container to the specified pressure storage container on receipt of a shift indication from the feeder, at a delivery of the gas to a subsequent tank carrier.