An electronic device (101,102,104,200) comprising: a first circuit board having a first connection terminal formed thereon; a first electronic component connected to the first connection terminal and disposed on the first circuit board; an interposer having a via formed therein and having a first surface attached to the first circuit board, the interposer at least partly surrounding at least a partial region of the first circuit board and a first end portion of the via being electrically connected to the first connection terminal, wherein the interposer comprises a ground region surrounding at least a part of the via; a second circuit board having a second connection terminal formed thereon and attached to a second surface of the interposer in an opposite direction to the first surface, the second connection terminal being electrically connected to a second end portion of the via and the second circuit board forming an inner space together with the first circuit board and the interposer; a second electronic component connected to the second connection terminal and disposed on the second circuit board; and an antenna electrically connected to the second electronic component; wherein the interposer further has a side plating member, and wherein the side plating member is formed on an upper surface, a side surface and a lower surface of the interposer on keep-out regions (236, 237) corresponding to regions of the interposer where part of the ground region has been removed, the side plating member and the via are connected to each other through an interconnect, and the side plating member is connected to the ground region through an extension part extending from the ground region. a first circuit board having a first connection terminal formed thereon; a first electronic component connected to the first connection terminal and disposed on the first circuit board; an interposer having a via formed therein and having a first surface attached to the first circuit board, the interposer at least partly surrounding at least a partial region of the first circuit board and a first end portion of the via being electrically connected to the first connection terminal, wherein the interposer comprises a ground region surrounding at least a part of the via; a second circuit board having a second connection terminal formed thereon and attached to a second surface of the interposer in an opposite direction to the first surface, the second connection terminal being electrically connected to a second end portion of the via and the second circuit board forming an inner space together with the first circuit board and the interposer; a second electronic component connected to the second connection terminal and disposed on the second circuit board; and an antenna electrically connected to the second electronic component; wherein the interposer further has a side plating member, and wherein the side plating member is formed on an upper surface, a side surface and a lower surface of the interposer on keep-out regions (236, 237) corresponding to regions of the interposer where part of the ground region has been removed, the side plating member and the via are connected to each other through an interconnect, and the side plating member is connected to the ground region through an extension part extending from the ground region.