An electronic device comprising: a housing including a first plate, a second plate facing away from the first plate, and a side housing surrounding a space between the first plate and the second plate and joined to the second plate or being integral with the second plate; a display viewable through at least part of the first plate; a first Printed Circuit Board, PCB, disposed between the first plate and the second plate and including at least one first ground layer; a Flexible Printed Circuit Board, FPCB, at least partially overlapping the first PCB when viewed from above the first plate, wherein the FPCB includes a first end electrically coupled to the first PCB, a second end, and at least one second ground layer; and a conductive structure electrically coupling the first ground layer of the first PCB and the second ground layer of the FPCB; and an antenna structure comprising at least one antenna electrically coupled to the second end of the FPCB and disposed between the first plate and the second plate, wherein the conductive structure supports the FPCB such that the FPCB maintains a state of being spaced apart from the first PCB, wherein the conductive structure includes: a first conductive portion electrically coupled at a first position of the first ground layer; a second conductive portion electrically coupled to the first ground layer at a second position, different from the first position; and a third conductive portion electrically coupled between the first portion of the conductive structure and the second portion of the conductive structure and electrically coupled with the second ground layer, wherein the third conductive portion is spaced apart from the first PCB. a housing including a first plate, a second plate facing away from the first plate, and a side housing surrounding a space between the first plate and the second plate and joined to the second plate or being integral with the second plate; a display viewable through at least part of the first plate; a first Printed Circuit Board, PCB, disposed between the first plate and the second plate and including at least one first ground layer; a Flexible Printed Circuit Board, FPCB, at least partially overlapping the first PCB when viewed from above the first plate, wherein the FPCB includes a first end electrically coupled to the first PCB, a second end, and at least one second ground layer; and a conductive structure electrically coupling the first ground layer of the first PCB and the second ground layer of the FPCB; and an antenna structure comprising at least one antenna electrically coupled to the second end of the FPCB and disposed between the first plate and the second plate, wherein the conductive structure supports the FPCB such that the FPCB maintains a state of being spaced apart from the first PCB, wherein the conductive structure includes: a first conductive portion electrically coupled at a first position of the first ground layer; a second conductive portion electrically coupled to the first ground layer at a second position, different from the first position; and a third conductive portion electrically coupled between the first portion of the conductive structure and the second portion of the conductive structure and electrically coupled with the second ground layer, wherein the third conductive portion is spaced apart from the first PCB. a first conductive portion electrically coupled at a first position of the first ground layer; a second conductive portion electrically coupled to the first ground layer at a second position, different from the first position; and a third conductive portion electrically coupled between the first portion of the conductive structure and the second portion of the conductive structure and electrically coupled with the second ground layer, wherein the third conductive portion is spaced apart from the first PCB.