An electronic device includes a housing including a first housing, and a second housing which is rotatably coupled to the first housing, a flexible display facing the first and second housings and including a folding area, a waterproof member between the housing and the flexible display, and a support structure between the housing and the flexible display, where the support structure includes a first part having a first height and a second part having a second height greater than the first height, and the second part is overlapping the folding area.