To provide a plasma torch which can speed up a working operation such as welding, cutting, by securing thermal energy sufficient for heating a workpiece.

In the plasma torch 20, a central electrode 21 and a first nozzle 22 are formed to be long and narrow in the advancing direction of welding. The flow of the plasma jetted from the first nozzle 22 becomes a comparatively narrow plasma flow PSMy when viewed from the advancing direction of welding, and the plasma arc between the central electrode 21 and a base material 30 for welding becomes a continuous arc with a required length in the advancing direction of welding by the long and narrow plasma flow. As a result, the welding operation can be performed by the following portion of the long and narrow plasma arc while preheating the base material by the leading portion of the long and narrow plasma arc. Therefore, the welding operation can be furthermore quickly performed compared with the plasma arc welding by the plasma torch having a conventional rod shape central electrode and a conventional cylindrical nozzle.