Tube-shaped pleated filter member

A tube-shaped pleated filter member comprising:

• a filter body having a tube shape in which a filter medium is wound after being pleated and extends, based on a central axis, in a longitudinal direction;
• and
• a support unit retaining the tube shape of the filter body,
• wherein the filter body includes outer pleated portions corresponding to an outside of the tube shape, and inner pleated portions corresponding to an inside of the tube shape, among the pleated portions of the filter medium,
• an inner virtual line formed by connecting corners of the inner pleated portions to each other on a plane perpendicular to the central axis of the filter body has a shape in which a unit wave shape recessed from the central axis of the filter body in an outward direction is repeated, and
• when a first thickness (T1) indicates a thickness of the filter body in a portion having a maximum distance between the inner virtual line and an outer virtual line with regard to the unit wave shape formed by the inner virtual line, the first thickness (T1) has a range of [Equation 1] with regard to a diameter (D) of the outer virtual line:
• D/15≤T1≤D/6. [Equation 1]