An electronic device comprising: a housing comprising: a front surface plate; a rear surface plate facing toward an opposite direction of the front surface plate; and a side surface member surrounding a space between the front surface plate and the rear surface plate, the side surface member having a substantially rectangular shape when viewed above the front surface plate, the side surface member comprising: a first portion having a first length and extending in a first direction; a second portion having a second length longer than the first length, and extending in a second direction perpendicular to the first direction; a third portion having the first length and extending in the first direction in parallel with the first portion; and a fourth portion having the second length and extending in the second direction in parallel with the second portion; a first wireless communication device, wherein the first wireless communication device includes: a first substrate perpendicular to the front surface plate, a first antenna array including a plurality of antenna elements arranged at regular intervals and disposed on a first surface of the first substrate, the first surface facing the side surface member, and a first wireless communication circuit disposed on a second surface of the first substrate, the second surface being opposite to the first surface, wherein the first wireless communication device is arranged adjacent to one side of the electronic device, wherein a first part of the side surface member facing the first wireless communication device is comprised of a non-conductive material, and wherein the first wireless communication device is configured to use a millimeter wave as an operating frequency band. a front surface plate; a rear surface plate facing toward an opposite direction of the front surface plate; and a side surface member surrounding a space between the front surface plate and the rear surface plate, the side surface member having a substantially rectangular shape when viewed above the front surface plate, the side surface member comprising: a first portion having a first length and extending in a first direction; a second portion having a second length longer than the first length, and extending in a second direction perpendicular to the first direction; a third portion having the first length and extending in the first direction in parallel with the first portion; and a fourth portion having the second length and extending in the second direction in parallel with the second portion; a first portion having a first length and extending in a first direction; a second portion having a second length longer than the first length, and extending in a second direction perpendicular to the first direction; a third portion having the first length and extending in the first direction in parallel with the first portion; and a fourth portion having the second length and extending in the second direction in parallel with the second portion; a first wireless communication device, wherein the first wireless communication device includes: a first substrate perpendicular to the front surface plate, a first antenna array including a plurality of antenna elements arranged at regular intervals and disposed on a first surface of the first substrate, the first surface facing the side surface member, and a first wireless communication circuit disposed on a second surface of the first substrate, the second surface being opposite to the first surface, wherein the first wireless communication device is arranged adjacent to one side of the electronic device, wherein a first part of the side surface member facing the first wireless communication device is comprised of a non-conductive material, and wherein the first wireless communication device is configured to use a millimeter wave as an operating frequency band. a first substrate perpendicular to the front surface plate, a first antenna array including a plurality of antenna elements arranged at regular intervals and disposed on a first surface of the first substrate, the first surface facing the side surface member, and a first wireless communication circuit disposed on a second surface of the first substrate, the second surface being opposite to the first surface, wherein the first wireless communication device is arranged adjacent to one side of the electronic device, wherein a first part of the side surface member facing the first wireless communication device is comprised of a non-conductive material, and wherein the first wireless communication device is configured to use a millimeter wave as an operating frequency band.