An electronic device comprising: a housing including: a first cover defining a front surface of the electronic device, a second cover defining a rear surface of the electronic device, and a bracket (110C, 300) defining a portion of a side surface of the electronic device, and surrounding a space between the first cover and the second cover; wherein the bracket includes metal, and has a recess formed therein; wherein the recess is opened towards the portion of the side surface of the electronic device, and the recess being partially defined by an inclined region of the bracket that extends towards the portion of the side surface of the electronic device; a display (101, 130) at least partially visible through a front surface of the first cover; an insulating structure, comprised by the bracket, disposed in the recess and coupled to the inclined region of the recess; and an antenna module including an antenna substrate including a conductive pattern, a first surface including a radiation area configured to radiate an RF signal from the conductive pattern, wherein the antenna module is disposed such that the RF signal is radiated through the insulating structure, wherein the conductive pattern is formed on or in the antenna substrate, wherein the antenna module is disposed in the recess, such that the first surface is perpendicular to the front surface and/or rear surface, wherein the bracket includes an inner wall (146, 310) including a resting region and further partially defining the recess, wherein the antenna module is disposed on the resting region of the inner wall (146, 310), and wherein the inclined region is inclined with respect to a direction that the inner wall faces so that the recess widens in the direction that the recess is opened towards. a housing including: a first cover defining a front surface of the electronic device, a second cover defining a rear surface of the electronic device, and a bracket (110C, 300) defining a portion of a side surface of the electronic device, and surrounding a space between the first cover and the second cover; a first cover defining a front surface of the electronic device, a second cover defining a rear surface of the electronic device, and a bracket (110C, 300) defining a portion of a side surface of the electronic device, and surrounding a space between the first cover and the second cover; wherein the bracket includes metal, and has a recess formed therein; wherein the recess is opened towards the portion of the side surface of the electronic device, and the recess being partially defined by an inclined region of the bracket that extends towards the portion of the side surface of the electronic device; a display (101, 130) at least partially visible through a front surface of the first cover; an insulating structure, comprised by the bracket, disposed in the recess and coupled to the inclined region of the recess; and an antenna module including an antenna substrate including a conductive pattern, a first surface including a radiation area configured to radiate an RF signal from the conductive pattern, wherein the antenna module is disposed such that the RF signal is radiated through the insulating structure, wherein the conductive pattern is formed on or in the antenna substrate, wherein the antenna module is disposed in the recess, such that the first surface is perpendicular to the front surface and/or rear surface, wherein the bracket includes an inner wall (146, 310) including a resting region and further partially defining the recess, wherein the antenna module is disposed on the resting region of the inner wall (146, 310), and wherein the inclined region is inclined with respect to a direction that the inner wall faces so that the recess widens in the direction that the recess is opened towards.