To prevent extraordinary temperature-rise within an incineration furnace, and also prevent dispersion of noxious gas and leakage of a toxic substance in incineration residual ashes by incorporating an inorganic compound having a BET specific surface area of a specific value or more after incineration in thermoplastic resin at a specific ratio relative to bag total weight.

As a material of a bag, thermoplastic resin is filled with an inorganic compound having a BET specific surface area of 30 m2/g or more after incineration at 10-50 wt.% relative to the bag total weight. Aluminum hydroxide (zeolite, clay, silicate or the like) is appropriate as an inorganic compound. Aluminum hydroxide releases crystal water in a high temperature condition in an incineration furnace, and is transited to an active alumina (transition alumina) having a high specific surface area. The reaction has an effect to reduce a combustion temperature in a furnace. An inorganic compound having a BET specific surface area of 30 m2/g or more after incineration absorbs harmful components such as HCl, dioxin, etc. In addition, the compound absorbs heavy metal ions in incineration residual ashes, and prevent them from being dissolved in reclaimed land.