An electronic device comprising: a housing including a front plate , a rear plate facing an opposite direction to the front plate , and a side member surrounding a space between the front plate and the rear plate and including a conductive annular member ; at least one mounting member connected to the side member and detachably mounted on a portion of a human body such that the rear plate faces the portion of the human body; a substrate, PCB, disposed in the space in parallel with the front plate and having a ground plane (G); at least one wireless communication circuit disposed on the substrate ; characterised in that the electronic device comprises: a first electrical path connected between the wireless communication circuit and a first point of the conductive annular member ; a second electrical path connected between the ground plane (G) and a second point of the conductive annular member in which a first region of the conductive annular member defined between the first point and the second point has a first length (E1) and a second region of the conductive annular member defined between the first point and the second point has a second length (E2) smaller than the first length (E1); and a conductive pattern disposed in the space, having an extension that extends along a portion of the first region or the second region of the annular member , and electrically connected to the wireless communication circuit . a housing including a front plate , a rear plate facing an opposite direction to the front plate , and a side member surrounding a space between the front plate and the rear plate and including a conductive annular member ; at least one mounting member connected to the side member and detachably mounted on a portion of a human body such that the rear plate faces the portion of the human body; a substrate, PCB, disposed in the space in parallel with the front plate and having a ground plane (G); at least one wireless communication circuit disposed on the substrate ; characterised in that the electronic device comprises: a first electrical path connected between the wireless communication circuit and a first point of the conductive annular member ; a second electrical path connected between the ground plane (G) and a second point of the conductive annular member in which a first region of the conductive annular member defined between the first point and the second point has a first length (E1) and a second region of the conductive annular member defined between the first point and the second point has a second length (E2) smaller than the first length (E1); and a conductive pattern disposed in the space, having an extension that extends along a portion of the first region or the second region of the annular member , and electrically connected to the wireless communication circuit . a first electrical path connected between the wireless communication circuit and a first point of the conductive annular member ; a second electrical path connected between the ground plane (G) and a second point of the conductive annular member in which a first region of the conductive annular member defined between the first point and the second point has a first length (E1) and a second region of the conductive annular member defined between the first point and the second point has a second length (E2) smaller than the first length (E1); and a conductive pattern disposed in the space, having an extension that extends along a portion of the first region or the second region of the annular member , and electrically connected to the wireless communication circuit . <EOS>