A foldable device comprising: a housing including a first housing and a second housing; a hinge structure coupled with the first housing and the second housing and accommodated in a hinge housing; and a flexible display accommodated in the first housing and the second housing; wherein the hinge structure includes: a first bracket coupled with the first housing and configured to rotate about a first axis; a second bracket coupled with the second housing and configured to rotate about a second axis; characterised in that the hinge structure further includes a first arm portion coupled with the first bracket, and including a first support rib protruding from one region of the first arm portion; a second arm portion coupled with the second bracket and including a second support rib protruding from one region of the second arm portion; a support portion at least partially disposed between the first arm portion and the second arm portion; and a stopper; and an elastic member, wherein the elastic member is in contact with one region of the stopper and is arranged such that the elastic member is deformed while the support portion is moved in a first direction opposite to the hinge housing by the first support rib of the first arm portion and the second support rib of the second arm portion, while the foldable device is being changed from the folded state to an unfolded state, wherein the support portion is configured to support at least one region of the flexible display when the foldable device is in the unfolded state, and wherein the support portion is moved in a second direction opposite to the first direction by the elastic restoration force of the elastic member, while the foldable device is being changed from the unfolded state to the folded state. a housing including a first housing and a second housing; a hinge structure coupled with the first housing and the second housing and accommodated in a hinge housing; and a flexible display accommodated in the first housing and the second housing; wherein the hinge structure includes: a first bracket coupled with the first housing and configured to rotate about a first axis; a second bracket coupled with the second housing and configured to rotate about a second axis; characterised in that the hinge structure further includes a first arm portion coupled with the first bracket, and including a first support rib protruding from one region of the first arm portion; a second arm portion coupled with the second bracket and including a second support rib protruding from one region of the second arm portion; a support portion at least partially disposed between the first arm portion and the second arm portion; and a stopper; and an elastic member, wherein the elastic member is in contact with one region of the stopper and is arranged such that the elastic member is deformed while the support portion is moved in a first direction opposite to the hinge housing by the first support rib of the first arm portion and the second support rib of the second arm portion, while the foldable device is being changed from the folded state to an unfolded state, wherein the support portion is configured to support at least one region of the flexible display when the foldable device is in the unfolded state, and wherein the support portion is moved in a second direction opposite to the first direction by the elastic restoration force of the elastic member, while the foldable device is being changed from the unfolded state to the folded state. a first bracket coupled with the first housing and configured to rotate about a first axis; a second bracket coupled with the second housing and configured to rotate about a second axis; characterised in that the hinge structure further includes a first arm portion coupled with the first bracket, and including a first support rib protruding from one region of the first arm portion; a second arm portion coupled with the second bracket and including a second support rib protruding from one region of the second arm portion; a support portion at least partially disposed between the first arm portion and the second arm portion; and a stopper; and an elastic member, wherein the elastic member is in contact with one region of the stopper and is arranged such that the elastic member is deformed while the support portion is moved in a first direction opposite to the hinge housing by the first support rib of the first arm portion and the second support rib of the second arm portion, while the foldable device is being changed from the folded state to an unfolded state, wherein the support portion is configured to support at least one region of the flexible display when the foldable device is in the unfolded state, and wherein the support portion is moved in a second direction opposite to the first direction by the elastic restoration force of the elastic member, while the foldable device is being changed from the unfolded state to the folded state.