A non-consumable electrode arc-welding method for causing a welding machine to output or stop a welding current (Iw) in accordance with at least an ON state and an OFF state of a start signal(Ts), the method comprising: switching between an ON state and an OFF state of a start signal (Ts) that controls an on/off operation of the welding machine; characterised in that: the method further comprises: switching between a normal mode and an interval mode of an operation mode instruction signal (Ms) controlling an operation mode of the welding machine, wherein: the welding machine comprises a welding output setting circuit configured to output a welding output signal (Ao), the welding machine having the start signal (Ts), the operation mode instruction signal (Ms), a welding current output period (Os) and a welding current interval period (Fs) as inputs; the welding machine is configured to receive the welding output signal (Ao) as an input and output the welding current (Iw) when the welding output signal (Ao) is input and not output the welding currently (Iw) when the welding output signal (Ao) is not input; when the operation mode instruction signal (Ms) indicates the normal mode and the start signal (Ts) is in the ON state, the welding output setting circuit outputs the welding output signal (Ao) such that the welding current (Iw) is outputted from the welding machine and; when the operation mode instruction signal (Ms) indicates the interval mode and the start signal is in the ON state, the welding output setting circuit outputs the welding output signal (Ao) such that the welding current (Iw) is outputted from the welding machine in the welding current output period (Os) and the welding output setting circuit does not output the welding output signal (Ao) such that the output of the welding current (Iw) from the welding machine is suspended in the welding current interval period (Fs) successively following the welding current output period (Os), wherein the output and the suspension of the welding current (Iw) are repeated while the start signal (Ts) is in the ON state. the welding machine comprises a welding output setting circuit configured to output a welding output signal (Ao), the welding machine having the start signal (Ts), the operation mode instruction signal (Ms), a welding current output period (Os) and a welding current interval period (Fs) as inputs; the welding machine is configured to receive the welding output signal (Ao) as an input and output the welding current (Iw) when the welding output signal (Ao) is input and not output the welding currently (Iw) when the welding output signal (Ao) is not input; when the operation mode instruction signal (Ms) indicates the normal mode and the start signal (Ts) is in the ON state, the welding output setting circuit outputs the welding output signal (Ao) such that the welding current (Iw) is outputted from the welding machine and; when the operation mode instruction signal (Ms) indicates the interval mode and the start signal is in the ON state, the welding output setting circuit outputs the welding output signal (Ao) such that the welding current (Iw) is outputted from the welding machine in the welding current output period (Os) and the welding output setting circuit does not output the welding output signal (Ao) such that the output of the welding current (Iw) from the welding machine is suspended in the welding current interval period (Fs) successively following the welding current output period (Os), wherein the output and the suspension of the welding current (Iw) are repeated while the start signal (Ts) is in the ON state.