An electronic device including: a first housing including a hinge recess formed on one side edge thereof; a second housing including a hinge protrusion formed on one side edge thereof, the hinge protrusion adapted to rotatably couple to the hinge recess; and an antenna device disposed in the first housing adjacent to the hinge recess, wherein the antenna device (103, 303, 403) comprises: a radiation conductor (133, 433a, 433b) disposed in the first housing; a reflection member (135, 435a, 435b) disposed adjacent to the radiation conductor (133, 433a, 433b) in the first housing, wherein radio waves transceived by the radiation conductor (133, 433a, 433b) are radiated via the reflection member (135, 435a, 435b); and an antenna carrier (131, 231) mounted on an inner face of the first housing and formed of an insulating material, wherein a face of the hinge recess includes an opening through which at least a portion of the antenna device (103, 303, 403) is exposed to an outside of the first housing, wherein the antenna carrier (131, 231) includes a body portion, and an extension portion protruding from a side face of the body portion, and the radiation conductor (133, 433a, 433b) and the reflection member (135, 435a, 435b) are mounted on the side face and the extension portion, respectively, wherein the radiation conductor (133, 433a, 433b) is disposed adjacent to the hinge recess, and the reflection member (135, 435a, 435b) is disposed between the radiation conductor (133, 433a, 433b) and the hinge recess. a first housing including a hinge recess formed on one side edge thereof; a second housing including a hinge protrusion formed on one side edge thereof, the hinge protrusion adapted to rotatably couple to the hinge recess; and an antenna device disposed in the first housing adjacent to the hinge recess, wherein the antenna device (103, 303, 403) comprises: a radiation conductor (133, 433a, 433b) disposed in the first housing; a reflection member (135, 435a, 435b) disposed adjacent to the radiation conductor (133, 433a, 433b) in the first housing, wherein radio waves transceived by the radiation conductor (133, 433a, 433b) are radiated via the reflection member (135, 435a, 435b); and an antenna carrier (131, 231) mounted on an inner face of the first housing and formed of an insulating material, a radiation conductor (133, 433a, 433b) disposed in the first housing; a reflection member (135, 435a, 435b) disposed adjacent to the radiation conductor (133, 433a, 433b) in the first housing, wherein radio waves transceived by the radiation conductor (133, 433a, 433b) are radiated via the reflection member (135, 435a, 435b); and an antenna carrier (131, 231) mounted on an inner face of the first housing and formed of an insulating material, wherein a face of the hinge recess includes an opening through which at least a portion of the antenna device (103, 303, 403) is exposed to an outside of the first housing, wherein the antenna carrier (131, 231) includes a body portion, and an extension portion protruding from a side face of the body portion, and the radiation conductor (133, 433a, 433b) and the reflection member (135, 435a, 435b) are mounted on the side face and the extension portion, respectively, wherein the radiation conductor (133, 433a, 433b) is disposed adjacent to the hinge recess, and the reflection member (135, 435a, 435b) is disposed between the radiation conductor (133, 433a, 433b) and the hinge recess.