PURPOSE: To perfectly filter ran exhaust gas produced after rad-wastes are incinerated by jointing a glass cloth to both the faces of a glass fiber nonwoven fabric ad attaching the glass cloth to the inside of a filter material support frame with the glass cloth curved in zigzags.

CONSTITUTION: A glass cloth 2 is jointed to both the faces of glass fiber nonwoven fabric 1 for the purpose of making a filter material. The filter material is attached to the inside of a filter support frame 3 composed of stainless steel and the like. In order to largely take a filter area, with the filter material curved in zigzags in the direction of exhaust gas flow it is attached. A separator 4 is bent in the form of projections and recesses, the filter material is sandwiched between both the sides of its ridge line part for the purpose of support and a longitudinal channel part formed of bending in the form of the projections and recesses is made an exhaust gas passage. Because the separator 4 is inserted in between both the sides of the filter material, the longitudinal channel part is utilized as an air passage for back blow. The glass fiber without weaving is reinforced against the back blow at the time of back washing and is not damaged because the glass cloth 2 is also applied to the outflow side of the glass fiber 1.