NOVELTY - The device has a long annular chamber (7) that is surrounded by a dielectric unit. A rectangular opening (8) is communicated to chamber. A plasma gas supply pipe (10) is provided to introduce a gas into the chamber. A coil (3) is provided in parallel to a surface formed by chamber. A high-frequency power source is connected to coil. A substrate mounting table (1) is provided such that the chamber is provided along a surface perpendicular to a surface formed by substrate mounting table, and a refrigerant flow path (13) is provided inside the dielectric unit inside chamber.    USE - Device for processing substrate by irradiating thermal plasma, used in manufacturing electronic devices such as thin-film transistor (TFT) and solar cell.    ADVANTAGE - The substrate mounting table is provided such that the chamber is provided along a surface perpendicular to a surface formed by the substrate mounting table, and a refrigerant flow path is provided inside the dielectric unit inside the chamber so that the plasma processing to the substrate is performed by irradiating the substrate with plasma by reactive gas or with plasma and the reactive gas flow at the same time. Thus, the substrate is processed at high speed while performing high-temperature heat treatment uniformly to the vicinity of the surface of the substrate for reduced time period. The inductively-coupled plasma torch unit is surrounded by a shield unit made of conductor which is entirely grounded. Thus, the leakage of high frequency is prevented efficiently while preventing undesirable abnormal discharge. Hence, cooling efficiency is improved effectively by the simple piping system while securing equivalent plasma generation efficiency.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for processing substrate by irradiating thermal plasma.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of the device for processing substrate by irradiating thermal plasma.    Substrate mounting table (1)    Coil (3)    Long annular chamber (7)    Rectangular opening (8)    Plasma gas supply pipe (10)    Refrigerant flow path (13)