Carbon nanowires and flat single-crystal graphite (0001) terraces have been competitively formed on a carbon-doped Ni(111) substrate, for the first time, only by a heat treatment in ultrahigh vacuum. The growth mechanism is interpreted in terms of a bulk-to-surface precipitation process of internal carbon atoms that were doped in a high-purity Ni(111) substrate in advance. The observed carbon nanowires are single wires or bundles. Nanometer-scale morphology and chemical properties of the wires have been clarified by low-energy electron diffraction, Auger electron spectroscopy and scanning tunneling microscopy (STM). A simple manipulation technique of a single carbon nanowire is demonstrated by STM.