Disclosed is an electronic device. The electronic device according to an embodiment may include a first device and a second device that are coupled to each other or spaced from each other. The first device may include a first housing, a first antenna element having a first electrical length for transmitting or receiving a signal in a first frequency band, a communication circuit disposed inside the first housing and for transmitting and receiving the signal of the first antenna element, and a first ground member electrically connected to the first antenna element. The second device may include a second antenna element having a second electrical length, a second housing, and a second ground member disposed inside the second housing. The first antenna element and the second antenna element may be connected to each other, and operate as a third antenna element having a third electrical length for transmitting and receiving a signal in a second frequency band while the first device and the second device are connected to each other. The first ground member and the second ground member may be electrically connected to each other while the first device and the second device are connected to each other. In addition, various embodiments as understood from the specification are also possible.