According to various embodiments, an electronic device may include a first structure including a first plate including a first face and a second face facing away from the first face, and a second structure including a second plate, which faces the second face of the first plate and has an opening formed therein, and a first side wall extending from a first end portion of the second plate. The first structure may be movable between an open state and a closed state with respect to the second structure in a first direction with respect to the second plate. The second structure may be positioned at a first position from the first side wall when the first structure is in the closed state and positioned at a second distance, which is greater than the first distance, from the first side wall when the first structure is in the open state. The electronic device may further include a flexible touch screen display. The flexible touch screen display may include a planar portion extending across at least part of the first face, mounted to the first face, and having a first width in a second direction perpendicular to the first direction, and a bendable portion extending from the planar portion and positioned from the planar portion to the inside of a space between the first side wall and the first structure when in the closed state. The bendable portion may include a first portion extending from one end of the planar portion and having the same width as the first width, and a second portion extending from the first portion, facing the second plate, and having a second width less than the first width. The second portion of the bendable portion may be exposed visually at least in part to the outside of the electronic device through the opening of the second plate. At least part of the first portion of the bendable portion may be configured to construct substantially the same plane as the planar portion when the first structure transitions from the closed state to the open state. Other various embodiments are possible.