Tool, machine tool, and processing method

A tool (10) for machining a workpiece in a processing machine has a machine side during operation, preferably standardized connection portion (11) for connecting the tool with a numerically controlled machine tool (30), a plasma duct (44) for guiding a plasma produced, and workpiece side during operation, the end of the plasma guide lying (44) outlet (13) with one or more Plasmaauslassen (22) for supplying the plasma to a workpiece surface.