An electronic device is provided including a first housing, a second housing that slides relative to the first housing, a flexible display configured such that a size of a region exposed on a front side of the electronic device is changed in response to a sliding motion of the second housing relative to the first housing, a heat radiating sheet disposed on at least a portion of a rear surface of the flexible display, and a flexible display support member disposed on a portion of a rear surface of the heat radiating sheet to support a portion of the flexible display. The flexible display support member includes a plurality of support bars that extend in a direction perpendicular to a sliding direction of the second housing. The plurality of support bars are spaced apart. The heat radiating sheet includes a plurality of folding portions, and at least portions of the heat radiating sheet are located in spaces separating the plurality of support bars.