An air cleaner assembly with support members includes an air cleaner body into which air flows from outside, an air cleaner cover which is fastened to the air cleaner body and from which the filteredair is exhausted, and an air filter installed between the air cleaner body and the air cleaner cover to filter foreign material, and which is installed at an intake pipe introducing air into an enginefrom outside, where a diffuser guiding the exhaust of the filtered air is installed at the air cleaner cover; and the supporting member, which supports an outside surface of the diffuser on the air cleaner body and the air cleaner cover and allows air to pass in a longitudinal direction of the diffuser, is installed at the air cleaner body and the air cleaner cover, respectively, thereby supporting the diffuser and tuning the intake sound by the air flowing therein.