Spiral patterns that have concave and convex surfaces were discovered on a bulk metallic glass (BMG), Zr55Cu30Al10Ni5 atom % alloy after electropolishing under certain conditions. The observed spiral pattern had a wavelength of 2.4 mu m and peaks that were 0.19 mu m high. Electropolishing produces smooth metal and alloy surfaces. These patterns depend on the spatiotemporal properties during electropolishing.