An electronic device including an interposer is provided. The electronic device includes a first circuit board having a first connection terminal formed thereon, an application processor (AP) connected to the first connection terminal and deployed 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, 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 communication processor (CP) connected to the second connection terminal and deployed on the second circuit board, and an antenna electrically connected to the CP.