In the filter element (E), a multiplicity of tubes (3) each formed of filtering material and having a substantially circular cross-section are arrranged side by side in a tubular assembly with the axes of the tubes lying parallel to one another; inter-tube openings are closed (52) at one end of the tubular assembly which serves as an inlet for a fluid to be filtered, whereas intra-tube openings are closed (53) at the opposite end of the tubular assembly; and the total cross-sectional area of all the inter-tube openings is smaller than the total cross-sectional area of all the intra-tube openings, but larger than the minimum cross-sectional area of a path through which the fluid is supplied to the tubular assembly. Specifically, one or more filtering materials (1,2) including a plurality of tubes (3) each having a substantially circular shape cross-section and connecting portions (12,22) interconnecting the adjacent tubes (3) are rolled into a spiral shape to provide the tubular assembly with the axes of the tubes arranged side by side parallel to one another.