PURPOSE: To obtain the title element which is easy in manufacture and working and capable of enlarging throughputs and capable of high-precision filtration or separating operation and also is broad in applications by fixing a conical main body bored with spiral slit holes on a single face of a conical frame plate provided with a porous structure.

CONSTITUTION: A conical main body 1 which is previously molded and worked to a conical shape is used and cutting work is performed for this main body 1 along the inside or the outside of a conical circumferential face toward the outer circumference from the center and fine spiral slit holes 2 are bored and also this conical main body 1 is fixed on the single face of a conical frame plate 4 which is previously molded into the same shape and has a porous structure. The slit holes 2 show e.g. triangular shapes in the cross section and triangular parts having acute triangular parts in the cross section are formed between adjacent holes 2.