In order to provide a gas fueling method capable of suppressing overheating of a tank immediately after a start of fueling, in the gas fueling method, an accumulator and a hydrogen tank are coupled to each other with a gas flow passage. In a main fueling control at and after the timing t2, a sensor-based value MAT of a temperature parameter of a measurement position Q1 is calculated on the basis of a detection value of a first station temperature sensor, and the fueling control is performed on the basis of the sensor-based value MAT. In an initial fueling control at the timing t0 to t2, a prediction value MAT_pred of the temperature parameter is calculated at the timing t2 on the basis of an ambient temperature value, a mass flow rate value, and a heat capacity. The fueling control is performed on the basis of the prediction value MAT_pred.