The present invention relates to a cover for an electronic device. The cover is attachable to an electronic device and includes a first plate having an opening, the first plate configured to cover a first part of a rear surface of the electronic device, a second plate disposed adjacent to the first plate and configured to cover a second part of the rear surface of the electronic device, a third plate disposed adjacent to the second plate and configured to cover a third part of the rear surface of the electronic device, a pen storage part coupled to the opening of the first plate, an outer skin configured to wrap one surface of each of the first plate, the second plate, and the third plate, and a hinge configured to rotatably couple the second plate and the third plate, wherein the first plate is rotatable within a first designated angle range with respect to the second plate via the outer skin, wherein the third plate is rotatable within a second designated angle range with respect to the second plate via the hinge, and wherein the first plate is formed of a first material, and the pen storage part is formed of a second material having a hardness different from a hardness of the first material.