An electronic device comprising: a housing including a plate forming at least a portion of a back surface of the electronic device, and a conductive portion forming at least a portion of a side surface of the electronic device; a display accommodated in the housing and viewable through a front surface of the electronic device; an antenna structure (601, 602) accommodated in the housing; a support member supporting the antenna structure (601, 602); and a non-conductive member placed between the display and the plate; wherein the antenna structure (601, 602) includes: a printed circuit board, and one or more antennas (232, 234, 236, 238) formed at the printed circuit board to face the side surface, wherein at least a portion of the non-conductive member is placed between the antenna structure (601, 602) and the side surface of the electronic device, wherein at least a first partial region of a surface of the non-conductive member faces the antenna structure (601, 602), wherein a progress path of a radio frequency signal radiated from the one or more antennas is changed when passing through the at least a first partial region, wherein the surface of the non-conductive member includes a second partial region and a separating wall placed between the at least a first partial region and the second partial region, and wherein the one or more antennas include: a first antenna formed at a first portion of the printed circuit board, and a second antenna formed at a second portion of the printed circuit board, and wherein, when viewed in a direction substantially perpendicular to the surface of the printed circuit board, the first antenna overlaps the at least a first partial region, the second antenna overlaps the second partial region, and the separating wall overlaps a third portion placed between the first portion and the second portion. a housing including a plate forming at least a portion of a back surface of the electronic device, and a conductive portion forming at least a portion of a side surface of the electronic device; a display accommodated in the housing and viewable through a front surface of the electronic device; an antenna structure (601, 602) accommodated in the housing; a support member supporting the antenna structure (601, 602); and a non-conductive member placed between the display and the plate; wherein the antenna structure (601, 602) includes: a printed circuit board, and one or more antennas (232, 234, 236, 238) formed at the printed circuit board to face the side surface, wherein at least a portion of the non-conductive member is placed between the antenna structure (601, 602) and the side surface of the electronic device, wherein at least a first partial region of a surface of the non-conductive member faces the antenna structure (601, 602), wherein a progress path of a radio frequency signal radiated from the one or more antennas is changed when passing through the at least a first partial region, wherein the surface of the non-conductive member includes a second partial region and a separating wall placed between the at least a first partial region and the second partial region, and wherein the one or more antennas include: a first antenna formed at a first portion of the printed circuit board, and a second antenna formed at a second portion of the printed circuit board, and wherein, when viewed in a direction substantially perpendicular to the surface of the printed circuit board, the first antenna overlaps the at least a first partial region, the second antenna overlaps the second partial region, and the separating wall overlaps a third portion placed between the first portion and the second portion. a printed circuit board, and one or more antennas (232, 234, 236, 238) formed at the printed circuit board to face the side surface, wherein at least a portion of the non-conductive member is placed between the antenna structure (601, 602) and the side surface of the electronic device, wherein at least a first partial region of a surface of the non-conductive member faces the antenna structure (601, 602), wherein a progress path of a radio frequency signal radiated from the one or more antennas is changed when passing through the at least a first partial region, wherein the surface of the non-conductive member includes a second partial region and a separating wall placed between the at least a first partial region and the second partial region, and wherein the one or more antennas include: a first antenna formed at a first portion of the printed circuit board, and a second antenna formed at a second portion of the printed circuit board, and wherein, when viewed in a direction substantially perpendicular to the surface of the printed circuit board, the first antenna overlaps the at least a first partial region, the second antenna overlaps the second partial region, and the separating wall overlaps a third portion placed between the first portion and the second portion. a first antenna formed at a first portion of the printed circuit board, and a second antenna formed at a second portion of the printed circuit board, and wherein, when viewed in a direction substantially perpendicular to the surface of the printed circuit board, the first antenna overlaps the at least a first partial region, the second antenna overlaps the second partial region, and the separating wall overlaps a third portion placed between the first portion and the second portion.