NOVELTY - A waste material containing an organic halogen compound is heat-processed using waste-material heat-treatment equipment having a heating furnace, an inert gas supplying apparatus, a waste gas circulation path, a waste gas cleaning apparatus and an air suction system. The waste material containing organic halogen compound is heat-processed in a heating furnace. An inert gas is supplied to the heating furnace by the inert gas supplying apparatus. Air is introduced into the waste gas circulation path by the air suction system.    USE - Method is used for heat-processing waste material, soil, sludge and debris (all claimed) containing organic halogen compound such as organochlorine compound such as polychlorinated biphenyl and organochlorine agrochemical.    ADVANTAGE - The waste material containing organic halogen compound is heat-processed efficiently.    DETAILED DESCRIPTION - A waste material containing an organic halogen compound is heat-processed using waste-material heat-treatment equipment having a heating furnace, an inert gas supplying apparatus, a waste gas circulation path, a waste gas cleaning apparatus and an air suction system. The waste material containing organic halogen compound is heat-processed in a heating furnace. An inert gas is supplied to the heating furnace by the inert gas supplying apparatus. The waste gas circulation path is connected to the heating furnace through the waste gas cleaning apparatus from waste gas exit of the heating furnace. Air is introduced into the waste gas circulation path by the air suction system. The concentration of carbon monoxide and concentration of oxygen in waste gas within the waste gas circulation path are measured. The available-oxygen concentration in the heating furnace is controlled to 0.01-3 volume% according to concentration of carbon monoxide and concentration of oxygen, by adjusting feed rate of inert gas and/or quantity of introduced air. The inert gas is nitrogen gas. An INDEPENDENT CLAIM is included for a heat-processing apparatus of waste material containing organic halogen compound.