An electronic device comprising: a first electronic device which comprises a first inner surface, a first outer surface, and first side surfaces disposed between the first inner and outer surfaces; a second electronic device which comprises a second inner surface, a second outer surface, and second side surfaces disposed between the second inner and outer surfaces; and a connecting portion which connects the first and second electronic devices, wherein the second electronic device comprises a folding portion in parallel with the connecting portion, and is folded or unfolded on the first electronic device, and wherein the folding portion comprises a plurality of folding members, characterised in that: the second electronic device further comprises at least one elastic body that penetrates the plurality of folding members, wherein the at least one elastic body is used for providing an additional folding force or unfolding force on the second electronic device when an initial force above a predetermined level to fold or unfold the second electronic device on the first electronic device is provided by a user, such that the remaining deformation to fold or unfold the second electronic device is performed automatically without any further force applied by the user; and wherein the at least one elastic body comprises at least one roll spring, wherein the roll spring has a curvature shaped section in a direction parallel to the folding portion, and wherein the roll spring is moveable between a first position in which the roll spring is disposed substantially flat and provides the folding force of the second electronic device, and a second position wherein the roll spring is disposed substantially in a rolled shape and provides the unfolding force of the second electronic device. a first electronic device which comprises a first inner surface, a first outer surface, and first side surfaces disposed between the first inner and outer surfaces; a second electronic device which comprises a second inner surface, a second outer surface, and second side surfaces disposed between the second inner and outer surfaces; and a connecting portion which connects the first and second electronic devices, wherein the second electronic device comprises a folding portion in parallel with the connecting portion, and is folded or unfolded on the first electronic device, and wherein the folding portion comprises a plurality of folding members, characterised in that: the second electronic device further comprises at least one elastic body that penetrates the plurality of folding members, wherein the at least one elastic body is used for providing an additional folding force or unfolding force on the second electronic device when an initial force above a predetermined level to fold or unfold the second electronic device on the first electronic device is provided by a user, such that the remaining deformation to fold or unfold the second electronic device is performed automatically without any further force applied by the user; and wherein the at least one elastic body comprises at least one roll spring, wherein the roll spring has a curvature shaped section in a direction parallel to the folding portion, and wherein the roll spring is moveable between a first position in which the roll spring is disposed substantially flat and provides the folding force of the second electronic device, and a second position wherein the roll spring is disposed substantially in a rolled shape and provides the unfolding force of the second electronic device. the second electronic device further comprises at least one elastic body that penetrates the plurality of folding members, wherein the at least one elastic body is used for providing an additional folding force or unfolding force on the second electronic device when an initial force above a predetermined level to fold or unfold the second electronic device on the first electronic device is provided by a user, such that the remaining deformation to fold or unfold the second electronic device is performed automatically without any further force applied by the user; and wherein the at least one elastic body comprises at least one roll spring, wherein the roll spring has a curvature shaped section in a direction parallel to the folding portion, and wherein the roll spring is moveable between a first position in which the roll spring is disposed substantially flat and provides the folding force of the second electronic device, and a second position wherein the roll spring is disposed substantially in a rolled shape and provides the unfolding force of the second electronic device.