An electronic device is provided. The electronic device includes a reflector sheet disposed under a display panel and a digitizer disposed under the reflector sheet. The digitizer may include a first circuit layer including a conductive circuit pattern arranged in a first direction, a second circuit layer including a conductive circuit pattern arranged in a second direction, and an insulating layer electrically isolating the first circuit layer and the second circuit layer. The digitizer further includes at least one dummy circuit pattern formed on at least one of the first circuit layer or the second circuit layer.