a sintered ceramic structure for cleaning noxious substances contained in the exhaust gases emitted by an internal combustion engine is disclosed . the stucture comprises : an exhaust - gas cleaning portion including a multiplicity of pores through which the exhaust gas is discharged and an exhaust - gas inlet portion and an exhaust - gas outlet portion ; an external wall portion being integrally disposed around the outer periphery of the exhaust - gas cleaning portion except for both the exhaust - gas inlet portion and the exhaust - gas outlet portion of the exhaust - gas cleaning portion ; the exhaust - gas cleaning portion and the external wall portion being constituted by ceramics ; and the ceramics of the external wall portion being composed of a sintered ceramic material having a sintering - shrinkage ratio smaller than that of the ceramics of the sintered ceramic material of the noxious gas cleaning portion , whereby upon sintering a residual compressive stress is imparted to the external wall portion due to the difference between the sintered - shrinkage ratios .