An electronic device detachably coupled to an electric terminal of an apparatus, the apparatus including an engagement portion adjacent to the electric terminal, the electronic device includes a rotation piece disposed at an insertion end portion of the electronic device, the rotation piece being rotated to engage the engagement portion disposed adjacent to the electric terminal; a connection member coupled to the rotation piece and configured to slide relative to the electronic device to rotate the rotation piece; and an operation lever coupled to the connection member and disposed at a removal end portion of the electronic device, the operation lever being interlocked with the rotation piece through the connection member.