An electronic device (101, 200, 300, 400, 800, 900) comprising: a housing (410, 910) comprising a front surface plate, a rear surface plate facing a direction opposite the front surface plate, and a side surface member surrounding a space between the front surface plate and the rear surface plate; at least one attachment member coupled to the side surface member, and removably fastened to a human body, the at least one attachment member comprising a first attachment member (420, 920) coupled to at least part of the side surface member, and a second attachment member (430, 930) coupled to a position of the side surface member facing the first attachment member; a substrate arranged in the space in parallel with the front surface plate; at least one wireless communication circuit (322, 324, 333, 451, 452) arranged on the substrate; a first conductive pattern electrically connected with the wireless communication circuit, and arranged on the side surface member in proximity to the first attachment member, the first conductive pattern comprising a radiating element; a second conductive pattern electrically connected with the wireless communication circuit, and arranged on the side surface member in proximity to the second attachment member, the second conductive pattern comprising a radiating element; characterized in that it further comprises a first conductive member arranged in the first attachment member (420, 920) in proximity to the first conductive pattern to be capacitively coupled with the first conductive pattern; and a second conductive member arranged in the second attachment member (430, 930) in proximity to the second conductive pattern to be capacitively coupled with the second conductive pattern. a housing (410, 910) comprising a front surface plate, a rear surface plate facing a direction opposite the front surface plate, and a side surface member surrounding a space between the front surface plate and the rear surface plate; at least one attachment member coupled to the side surface member, and removably fastened to a human body, the at least one attachment member comprising a first attachment member (420, 920) coupled to at least part of the side surface member, and a second attachment member (430, 930) coupled to a position of the side surface member facing the first attachment member; a substrate arranged in the space in parallel with the front surface plate; at least one wireless communication circuit (322, 324, 333, 451, 452) arranged on the substrate; a first conductive pattern electrically connected with the wireless communication circuit, and arranged on the side surface member in proximity to the first attachment member, the first conductive pattern comprising a radiating element; a second conductive pattern electrically connected with the wireless communication circuit, and arranged on the side surface member in proximity to the second attachment member, the second conductive pattern comprising a radiating element; characterized in that it further comprises a first conductive member arranged in the first attachment member (420, 920) in proximity to the first conductive pattern to be capacitively coupled with the first conductive pattern; and a second conductive member arranged in the second attachment member (430, 930) in proximity to the second conductive pattern to be capacitively coupled with the second conductive pattern.