PURPOSE: To increase filter efficiency, by bonding faces located on the inner sides of both ends of filter elements of crimps each other.

CONSTITUTION: A number of crimps 4 are formed by folding a sheet-shaped filter paper, and sealing sections 5 are also formed by bonding faces each other located on the inner sides of elements 3 of crimps 4 at both ends of filter elements 3 formed by rolling the sheet-shaped filter paper in the form of a cylinder. As a result, fluid to be filtered flows in the axial direction from one edge face to the other edge face of the element 3 in a constant flow velocity, and in said flow in the axial direction, the fluid to be filtered flows through from the outer side into the inner side of the element 3 and filtered. By said process, the pressure loss less than that of conventional elements, in which fluid to be filtered flows from the outer edge side into the inner edge side, can be provided, and uniform filtration at each section of the filter element 3 can be carried out by the constant flow to increase filter efficiency.