The objective of the present invention is to provide a plasma burner having an arc of 1-3 cm diameter, and a large volume arc jet near a nozzle neck in order to process a large flow of liquid fuel by plasma generated by supplying electric power of several tens to several hundreds of kW forming an elongated arc. According to an embodiment of the present invention, the plasma burner comprises: an accommodation unit which provides discharge air and has a first space; the nozzle neck which has a minimum diameter on the end of the first space, and a second space gradually expanding; a housing including an expanding unit extended from the nozzle neck and gradually expanding; an installation unit combined with the end of the accommodation unit and seals one side of the first space; an electrode installed in the installation unit and is located in the first space which has the elongated arc extended to the nozzle neck; and a nozzle installed in the nozzle neck in order to spray at least one of fuel and air.
