A filter structure comprising: a housing body formed in a cylindrical shape to have a first accommodating space and having an upper opening portion; a housing cap coupled to the upper opening portion of the housing body by a portion thereof being formed in a cylindrical shape and having a second accommodating space, wherein the housing cap has an upper opening portion, a coupling projection formed on an outer circumferential surface thereof and a housing fastening portion formed on an inner circumferential surface thereof; a filtering member having a cylindrical shape accommodated in the first accommodating space; and an upper supporter accommodated in the second accommodating space of the housing cap, wherein the upper supporter includes: a supporter accommodating portion coupled to an upper portion of the filtering member; a supporter fastening portion for preventing a rotation of the upper supporter in the housing cap by being coupled to the housing fastening portion; a supporter stepped portion integrally formed on an upper portion of the supporter accommodating portion; and a supporter extending portion which extends upward from the supporter stepped portion, wherein a first filter inlet flow path is formed on a center portion of the supporter extending portion, a second filter inlet flow path is formed on an outer circumferential surface of the supporter stepped portion; characterized in that: the first filter inlet flow path communicates with the second filter inlet flow path, and wherein a filter outlet flow path is formed on an outside of the first filter inlet flow path; a connecting portion is formed on an upper end of the supporter extending portion and is formed to be recessed toward the inside from the upper end of the supporter extending portion, and at least one projecting portion is formed in the supporter extending portion at an upper portion of the first filter inlet flow path. a housing body formed in a cylindrical shape to have a first accommodating space and having an upper opening portion; a housing cap coupled to the upper opening portion of the housing body by a portion thereof being formed in a cylindrical shape and having a second accommodating space, wherein the housing cap has an upper opening portion, a coupling projection formed on an outer circumferential surface thereof and a housing fastening portion formed on an inner circumferential surface thereof; a filtering member having a cylindrical shape accommodated in the first accommodating space; and an upper supporter accommodated in the second accommodating space of the housing cap, wherein the upper supporter includes: a supporter accommodating portion coupled to an upper portion of the filtering member; a supporter fastening portion for preventing a rotation of the upper supporter in the housing cap by being coupled to the housing fastening portion; a supporter stepped portion integrally formed on an upper portion of the supporter accommodating portion; and a supporter extending portion which extends upward from the supporter stepped portion, wherein a first filter inlet flow path is formed on a center portion of the supporter extending portion, a second filter inlet flow path is formed on an outer circumferential surface of the supporter stepped portion; characterized in that: the first filter inlet flow path communicates with the second filter inlet flow path, and wherein a filter outlet flow path is formed on an outside of the first filter inlet flow path; a connecting portion is formed on an upper end of the supporter extending portion and is formed to be recessed toward the inside from the upper end of the supporter extending portion, and at least one projecting portion is formed in the supporter extending portion at an upper portion of the first filter inlet flow path. a supporter accommodating portion coupled to an upper portion of the filtering member; a supporter fastening portion for preventing a rotation of the upper supporter in the housing cap by being coupled to the housing fastening portion; a supporter stepped portion integrally formed on an upper portion of the supporter accommodating portion; and a supporter extending portion which extends upward from the supporter stepped portion, wherein a first filter inlet flow path is formed on a center portion of the supporter extending portion, a second filter inlet flow path is formed on an outer circumferential surface of the supporter stepped portion; the first filter inlet flow path communicates with the second filter inlet flow path, and wherein a filter outlet flow path is formed on an outside of the first filter inlet flow path; a connecting portion is formed on an upper end of the supporter extending portion and is formed to be recessed toward the inside from the upper end of the supporter extending portion, and at least one projecting portion is formed in the supporter extending portion at an upper portion of the first filter inlet flow path.