PROBLEM TO BE SOLVED: To provide an ion beam processing method in which damages due to heat are not caused to a cross-section and the processing surface does not have roughness in the cross-section processing by irradiation of ion beams. SOLUTION: The ion beam processing device includes: an ion gun 2 to discharge ion beams on a test piece 6 to be processed; and a shielding plate 7 which installs the test piece on the lower side and shields a part of the ion beams. A heat conduction member 8 is installed in contact with the side face 6a on the cross-section-forming side of the test piece 6 and the upper side 6c of the test piece is made to project while slightly shifted from the end part 7a of the shielding plate to form the processing part 6b, and ion beams 4 are emitted on the upper face 6c of the processed part 6b and the upper face 8b near the side face of the heat conduction member 8, and the processed part 6b of the test piece 6 is ground to carry out processing treatment. Even if heat is generated by the processing treatment, the heat is discharged to the outside through the heat conduction member 8, and roughness of the cross-section caused by damages by heat can be avoided. COPYRIGHT: (C)2011,JPO&INPIT
