For understanding of nanometric chip removal process and in quest of extreme machining accuracy attainable, a carefully controlled microcutting experiment of electroplated copper was carried out on the-state-of-the-art experimental cutting machine and diamond cutting tool. Following a brief look at the significance of the minimum thickness of cut, which is defined as the minimum uncut thickness of chip removed from worksurface at a cutting edge under an ideal operation of machine tool, the chip morphology observed with high resolution scanning electron microscope (SEM) is discussed. SEM observation shows that the stable shear-banded chip can be removed even at nanometric uncut chip thickness. The chips are corrugated and folded due to the intermittent buckling of chip. Judging from the facts that the thickness, lamellar spacing and folding interval of chips continuously decrease with the uncut chip thickness, the mechanism of nanometric chip removel process seems to be same as that of conventional cutting. Finally, careful analysis of the experiment shows that the minimum thickness of cut of 1 nm can be expected in the microcutting of copper.