Disclosed is an electronic device including a housing, a wireless communication module, and an antenna module operatively connected to the wireless communication module and disposed inside the housing, wherein the antenna module includes a first substrate comprising at least one feed line, a first surface disposed in a first direction, and a second surface disposed in a second direction opposite the first surface, a second substrate disposed on the first surface of the first substrate and having a first antenna array and a second antenna array disposed on the second substrate, and a third substrate disposed in a portion of the second surface of the first substrate and having a third antenna array and a fourth antenna array disposed on the third substrate, wherein the second substrate and/or the third substrate is formed of a material having a higher permittivity than the first substrate.