An electronic device comprising: a housing including: a front plate, a rear plate facing in a direction opposite to the front plate, a lateral member surrounding a space between the front plate and the rear plate, wherein at least a part of the lateral member includes at least one conductive portion positioned between a first non-conductive portion and a second non-conductive portion which are spaced apart from each other, and a support member extended from the lateral member toward the space and including a conductive part and a polymer part formed into one body with the conductive part through insert injection; a conductive extended portion integrally extended from at least a part of the conductive portion to the space between the front plate and the rear plate; a printed circuit board disposed in the space between the front plate and the rear plate; and a wireless communication circuit disposed on the printed circuit board and electrically connected to the conductive portion at a first location of the conductive portion spaced apart from the first non-conductive portion, wherein the first non-conductive portion and the second non-conductive portion are extended from the polymer part, wherein the first non-conductive portion, the second non-conductive portion and the polymer part are formed together by insert-injection process, and wherein the conductive extended portion is supported by being insert-injected together with the polymer part in the space. a housing including: a front plate, a rear plate facing in a direction opposite to the front plate, a lateral member surrounding a space between the front plate and the rear plate, wherein at least a part of the lateral member includes at least one conductive portion positioned between a first non-conductive portion and a second non-conductive portion which are spaced apart from each other, and a support member extended from the lateral member toward the space and including a conductive part and a polymer part formed into one body with the conductive part through insert injection; a front plate, a rear plate facing in a direction opposite to the front plate, a lateral member surrounding a space between the front plate and the rear plate, wherein at least a part of the lateral member includes at least one conductive portion positioned between a first non-conductive portion and a second non-conductive portion which are spaced apart from each other, and a support member extended from the lateral member toward the space and including a conductive part and a polymer part formed into one body with the conductive part through insert injection; a conductive extended portion integrally extended from at least a part of the conductive portion to the space between the front plate and the rear plate; a printed circuit board disposed in the space between the front plate and the rear plate; and a wireless communication circuit disposed on the printed circuit board and electrically connected to the conductive portion at a first location of the conductive portion spaced apart from the first non-conductive portion, wherein the first non-conductive portion and the second non-conductive portion are extended from the polymer part, wherein the first non-conductive portion, the second non-conductive portion and the polymer part are formed together by insert-injection process, and wherein the conductive extended portion is supported by being insert-injected together with the polymer part in the space.