Abstract: An air filter element consists of an annularly arranged pleated filter medium having a plurality of radially extending pleats. Two sides or legs of each pleat are bonded to each other at the outer peripheral side to form an outer bonded section while one sides or legs of the adjacent pleats are bonded to each other at the inner peripheral side to form an inner bonded section, thereby forming a fluid path extending between the adjacent pleats along the length of each pleat. Additionally, outer and inner resilient seal members are so provided that a part of each outer bonded section is embedded in the outer seal member while a part of each inner bonded section is embedded in the inner sealing member.