Breakage for rock or concrete using high pressure gases generated by polyoxymethylene (TOM) decomposition based on zippering phenomena is reported. The rapid decomposition of POM is induced by pulse energy from an exothermic reaction of Cu OAl or CaO₂-Al composition. The mixture of POM and hermit composition is activated by electric discharge from condensers. The maximum pressure and its reacting time are similar to those of known black powder.