Method of manufacturing ceramic honeycomb-structural body

A process for producing a honeycomb-structural body, comprising the steps of:

• preparing a mixture of ceramic material and at least one component selected from the group consisting of molding aids and pore-forming agents;
• preparing an extrudable green ceramic material from said mixture;
• extruding said prepared extrudable green ceramic material to form a honeycomb-structural body;
• providing a first thermocouple in a through-hole of said honeycomb-structural body and a second thermocouple outside said honeycomb-structural body;
• and
• firing said honeycomb-structural body in a firing atmosphere while minimizing a differential temperature condition measured between interior and exterior portions of said honeycomb-structural body by increasing the oxygen concentration in the firing atmosphere in a range of firing temperatures which is outside a temperature range within which thermal decomposition of said at least one component occurs, and decreasing the oxygen concentration in the firing atmosphere in a range of firing temperatures which corresponds to said temperature range within which thermal decomposition of said at least one component occurs;
• wherein said at least one component is substantially completely removed from said honeycomb-structural body during said firing as a result of said increasing and said decreasing oxygen concentration in the firing atmosphere.