An electronic device is provided that includes a housing and a flexible display including a bendable section that may be extracted from an inner space of the housing. The electronic device also includes a support member positioned at least partially in the inner space of the housing and including a first surface facing the bendable section with a separation distance therebetween, and a dielectric disposed in the first surface while facing the bendable section and electrically connected to a ground. The electronic device also includes a sensor integrated circuit (IC) electrically connected to a touch sensing circuit included in the flexible display and configured to detect capacitance of a touch area facing the dielectric in the touch sensing circuit.