An arm structure of an electronic device is provided. The arm structure includes an arm body, a first cam disposed on one side of the arm body and including a first hole into which at least a portion of a rotating shaft providing a folding operation of the electronic device is inserted, a peak and a valley being formed around the first hole, a second cam arranged side-by-side on a same axis as the one side of the arm body, spaced apart from the first cam, and including a second hole into which at least a portion of the rotating shaft is inserted, a peak and a valley being formed around the second hole, and a connecting part disposed on another side of the arm body and fastened with a rotating part providing rotation of the electronic device.