PURPOSE: To provide a thread fastening machine capable of thread-fastening easily even if the threaded hole of a terminal part does not coincide with the threaded hole of a structure body due to the low bending accuracy and poor fitting state of a connecting plate at the time of thread-fastening one terminal part of the connecting plate bent in Z-shape to the structure body.

CONSTITUTION: The lower end part side faces of the screw guide 4 of a thread fastening machine 1 are provided with protruding plates 24 protruding radially along an axis so that the outer edges are protruded outside. The screw guide 4 is lower together with a driver 3 attraction holding a tapping screw 5. Before the tapping screw 5 reaches the terminal part 9 of a connecting plate 6, the straight line part 11 of the connecting plate 6 is pressed by the outer edge 23 of the protruding plate 24 so as to make the threaded hole 7 of the terminal part 9 coincide with the threaded holes 16, 14 of a module board 17 and a cooling fin 15.