A control device of a gas charging device controls opening/closing of a control valve so that pressure increase rate of gas pressure in a tank when gas charging to the tank increases at a reference increase rate determined in advance. The control device, when gas charge to the tank begins, controls pressure increase rate at a high increase rate higher than the reference increase rate. After the difference between gas pressure in the tank when gas charging is performed at the high increase rate and gas pressure in the tank when the charging is performed at the reference increase rate has reached a predetermined pressure difference, the control device controls the opening/closing of the control valve so that gas charge to the tank is performed at the reference increase rate.