Incinerator of the present invention is to seal the beds around the pulsation furnace or move two of the furnace,. These sealing portion, reducing the to enter and exit the contaminated gas in the main combustion chamber of the incinerator with a moving furnace, or to prevent. The sealing portion is used water, sand, or a filled container with a fluid, such as a material such as gravel. These sealing portions, the heat resistance of the film material to be adhered to relatively moving parts, is fixed to a portion, it is held against the other part, such as spring stainless steel or heat-resistant fiber of corrosion resistance during soft elastic material or moving parts, it has a heat resistance of a fibrous pad containing alumina oxide or silicon oxide fibers. Air knife, hold the combustion gas into the combustion furnace. The combination of these different sealing, the secondary adverse effects of prevention in the case of using only isolation and one of the surrounding can be achieved.