A microwave plasma nozzle configured to be connected to a microwave cavity, for generating plasma (28, 68, 80, 328) from microwaves and a gas, comprising: a gas flow tube (40, 54, 66, 78, 94, 104, 114, 124, 134, 146, 162, 170, 178, 186, 195, 508, 540) for having a gas flow therethrough, said gas flow tube (40, 54, 66, 78, 94, 104, 114, 124, 134, 146, 162, 170, 178, 186, 195, 508, 540) having an outlet portion including a material that is substantially transparent to microwaves; and a rod-shaped conductor (34, 50, 62, 74, 92, 102, 112, 122, 132, 144, 166, 182, 188, 194, 200, 202, 208, 212, 216, 221, 224, 228, 234, 502, 524) disposed in said gas flow tube (40, 54, 66, 78, 94, 104, 114, 124, 134, 146, 162, 170, 178, 186, 195, 508, 540), characterized in that said gas flow tube extends outside such a cavity, wherein said rod-shaped conductor (34, 50, 62, 74, 92, 102, 112, 122, 132, 144, 166, 182, 188, 194, 200, 202, 208, 212, 216, 221, 224, 228, 234, 502, 524), having a tip (33, 210, 214, 218, 236) and a collection portion (35, 504), receives microwaves at the collection portion (35, 504) and transmits the received microwaves along the surface thereof and focuses the microwaves at said tip (33, 210, 214, 218, 236), wherein said collection portion (35, 504) of said rod-shaped conductor (34, 50, 62, 74, 92, 102, 112, 122, 132, 144, 166, 182, 188, 194, 200, 202, 208, 212, 216, 221, 224, 228, 234, 502, 524) is disposed in the microwave cavity (24, 70, 324) and said tip (33, 210, 214, 218, 236) of said rod-shaped conductor (34, 50, 62, 74, 92, 102, 112, 122, 132, 144, 166, 182, 188, 194, 200, 202, 208, 212, 216, 221, 224, 228, 234, 502, 524) is disposed in proximity to said outlet portion of said gas flow tube (40, 54, 66, 78, 94, 104, 114, 124, 134, 146, 162, 170, 178, 186, 195, 508, 540), wherein said outlet portion refers to a section including the edge and a portion of said gas flow tube (40, 54, 66, 78, 94, 104, 114, 124, 134, 146, 162, 170, 178, 186, 195, 508, 540) in the proximity to said edge which are located outside the microwave cavity (24, 70, 324). a gas flow tube (40, 54, 66, 78, 94, 104, 114, 124, 134, 146, 162, 170, 178, 186, 195, 508, 540) for having a gas flow therethrough, said gas flow tube (40, 54, 66, 78, 94, 104, 114, 124, 134, 146, 162, 170, 178, 186, 195, 508, 540) having an outlet portion including a material that is substantially transparent to microwaves; and a rod-shaped conductor (34, 50, 62, 74, 92, 102, 112, 122, 132, 144, 166, 182, 188, 194, 200, 202, 208, 212, 216, 221, 224, 228, 234, 502, 524) disposed in said gas flow tube (40, 54, 66, 78, 94, 104, 114, 124, 134, 146, 162, 170, 178, 186, 195, 508, 540), characterized in that said gas flow tube extends outside such a cavity, wherein said rod-shaped conductor (34, 50, 62, 74, 92, 102, 112, 122, 132, 144, 166, 182, 188, 194, 200, 202, 208, 212, 216, 221, 224, 228, 234, 502, 524), having a tip (33, 210, 214, 218, 236) and a collection portion (35, 504), receives microwaves at the collection portion (35, 504) and transmits the received microwaves along the surface thereof and focuses the microwaves at said tip (33, 210, 214, 218, 236), wherein said collection portion (35, 504) of said rod-shaped conductor (34, 50, 62, 74, 92, 102, 112, 122, 132, 144, 166, 182, 188, 194, 200, 202, 208, 212, 216, 221, 224, 228, 234, 502, 524) is disposed in the microwave cavity (24, 70, 324) and said tip (33, 210, 214, 218, 236) of said rod-shaped conductor (34, 50, 62, 74, 92, 102, 112, 122, 132, 144, 166, 182, 188, 194, 200, 202, 208, 212, 216, 221, 224, 228, 234, 502, 524) is disposed in proximity to said outlet portion of said gas flow tube (40, 54, 66, 78, 94, 104, 114, 124, 134, 146, 162, 170, 178, 186, 195, 508, 540), wherein said outlet portion refers to a section including the edge and a portion of said gas flow tube (40, 54, 66, 78, 94, 104, 114, 124, 134, 146, 162, 170, 178, 186, 195, 508, 540) in the proximity to said edge which are located outside the microwave cavity (24, 70, 324).