a ribbon diaphragm generates cooperating with a magnet a tightening member for securing the ribbon diaphragm and a screw for crimping the tightening member wherein the tightening member is crimped via the ribbon diaphragm and the electrode lead portion by the screw and wherein the ribbon diaphragm includes a portion sandwiched by the tightening member and the portion is formed in an irregular shape in the thickness direction application_number US 27692308 A description an embodiment of a ribbon microphone unit according to the present invention will be described with reference to the accompanying drawings fig4 a and 4b show an embodiment of the ribbon microphone unit according to the present invention the ribbon microphone unit shown in fig4 a comprises a frame 7 a magnet 4 an electrode lead portion 18 a terminal strip 9 a tightening member comprising a pressure plate 8 and a support plate 81 a screw 10 and a ribbon diaphragm 60 the frame 7 is formed in a rectangular frame shape that is long in the longitudinal direction and a screw hole for securing to the microphone case 1 is formed at four corners on the inner surface of the frame 7 a pair of permanent magnets 4 4 is fixed on both sides along the longitudinal direction with a predetermined spacing between the both permanent magnets 4 4 the frame 7 is made of a magnetic material functions as a yoke and constitutes a magnetic circuit that goes out of the permanent magnets 4 4 and returns to the permanent magnets 4 4 the magnetization directions of the permanent magnets 4 4 are the same.