Two different recognition processing units respectively perform a plurality of different recognition processing operations for the pattern to be recognized input from a character input unit, and acquire a plurality of recognition candidates and recognition scores. According to the invention, the gas inlet chambers are closed off toward the process chamber by annular walls, wherein the annular walls comprise a plurality a gas outlet openings arranged closely next to each other, have a uniform outside diameter, and an outer wall that is substantially without projections and directed toward the process chamber. If the feed torque value is smaller than the reference torque value the welding wire is retracted and the distal end of the welding wire is separated from the base material and an initial arc is generated between the welding wire and the base material. If none are identified, the element is broken into sub-textual units that may contain a prefix, compound-prefix, andor suffix along with a primary element.