Pyrolysis and gasification with steam of coal were examined at high temperatures up to 2700℃ using a tantalum-made reactor by 500W YAG laser heating. Yield of product gases of H_2, CO_2, CO and CH_4 decreased with temperature increase up to 2000℃. However, at 2700℃, those all yields were increased. Especially, increase of hydrogen yield was predominant. It was, therefore, suggested that there is an effect of direct pyrolysis of H_2O at high temperature more than 2000℃.
