This paper describes development of self-heated stage suitable for thermal reactive ion etching (TRIE) of the functional metals. Thermal reactive ion etching was evaluated using both experiments and simulations for etching functional metals. The self-heated stage was designed based on the simulation results. TRIE employs a self-heated stage which is thermally insulated aluminum plate as the etching stage of a regular RIE apparatus. The stage temperature increases rapidly within 10 min and etch rate is not depend on process time. TRIE technique was used to etch various kinds of functional metals: Ti, Mo, Ta, Nb, and Ti alloy (Ti-6Al-4V). It did improve the etching rate of these materials greatly.