This study described characteristics of product gases emitted during high temperature pyrolysis of sewage sludge in the temperature range of 800 ~ 1,200oC for determining the possibility of energy recovery as one of the sewage sludge treatment methods. Char yield of each sewage sludge decreased with increasing reaction temperature until 1,000oC during pyrolysis experiment, but above 1,000oC it is nearly constant due to the total release of volatile matter contained in samples. Major gas components emitted from high temperature pyrolysis experiment of sewage sludges are CO2, H2, CO, and CH4. These major combustible gases except CO2 can be used as major energy source. Also major sulfur-containing gases known as the pollutant gas emitted during high temperature pyrolysis experiments are H2S, COS, and CS2. The principal sulfur gaseous product is H2S and concentrations of H2S and CS2 increases with increasing temperature, but in the case of COS its concentration is nearly constant with variation of temperature. So efficient treatment of sulfurcontaining gases emitted from thermal treatment of sewage sludge should be needed.