The stress field induced in the work by the arrival of powder particle is analysed. The finished surface by the arrival of various powder particles at the various angles are observed with the electron microscope and the electron diffraction method. It is clarified how the finished surface structure depends on the shape of the stress field and its strength, or on the powder particle size and the arrival angle. Furthermore, the machining condition for achieving better "Elastic Emission Machining" is investigated. It becomes evident that when the particle size and the arrival angle are smaller the work is finished without introducing the lattice defect, and by the arrival of fine powder particle almost parallel to the work surface the atomic size fracture can be introduced elastically and the geometrically and crystallographically perfect mirror surface is obtained.
