By using a steam plasma gasification system, PS resin and its compounds have been completely decomposed and converted into low-molecular-weight gases dominantly carbon monoxide(CO) and hydrogen gas(H2). Product gases on so-called synthetic gas obtained as a fuel containing 55% of H2 and 30% of CO under C/O ratio of 1.2 and a gasification temperature 1400℃ in the first chamber, respectively. The operation of a steam plasma torch and gasification system is stable and reliable within the necessary range of parameters.