An electronic device comprising: a first electronic device; an exterior cover including a first folding axis (fl) dividing the exterior cover into a first portion and a second portion, wherein the first electronic device is mountable on the first portion, wherein the second portion comprises one or more hinge axes (f2, f3), and wherein the exterior cover is configured to be folded two or more times with respect to the first folding axis (fl) and the one or more hinge axes (f2, f3) to support a second electronic device in an inclined state so as to form a triangle shape; and a buttress (340, 640, 840) disposed on a front face of the first electronic device, configured to be connected to the inclined second electronic device, and configured to support the inclined second electronic device, at least one elastic unit (313, 314); wherein the buttress is disposed in an accommodation portion formed on the front face of the first electronic device, the buttress being configured to be rotatable, and the accommodation portion having a first end and a second end opposite the first end, wherein, the first folding axis (fl) and the one or more hinge axes (f2, f3) are parallel to the accommodation portion and, when folded, the one or more hinge axes (f2, f3) are configured to divide the second portion into at least a first support and a second support, wherein the at least one elastic unit (313, 314) is disposed on at least one of the first end and the second end of the accommodation portion and the at least one elastic unit is configured to face the buttress, wherein at least a portion of the at least one elastic unit is configured to interlock with at least a portion of the buttress according to a rotational movement of the buttress, so as to minimize rocking or movement where the second electronic device is supported in the inclined state, and wherein the buttress includes: a first outer face exposed to the outside that includes at least one connection terminal disposed in a central region to be elastically movable; and a second inner face opposite to the first outer face that includes a plurality of first magnets that are mounted at regular intervals along a longitudinal direction to provide a force to minimize a rocking or moving of the buttress relative to the second electronic device, wherein the first electronic device includes a metal member corresponding to the plurality of magnets on the accommodation portion. a first electronic device; an exterior cover including a first folding axis (fl) dividing the exterior cover into a first portion and a second portion, wherein the first electronic device is mountable on the first portion, wherein the second portion comprises one or more hinge axes (f2, f3), and wherein the exterior cover is configured to be folded two or more times with respect to the first folding axis (fl) and the one or more hinge axes (f2, f3) to support a second electronic device in an inclined state so as to form a triangle shape; and a buttress (340, 640, 840) disposed on a front face of the first electronic device, configured to be connected to the inclined second electronic device, and configured to support the inclined second electronic device, at least one elastic unit (313, 314); wherein the buttress is disposed in an accommodation portion formed on the front face of the first electronic device, the buttress being configured to be rotatable, and the accommodation portion having a first end and a second end opposite the first end, wherein, the first folding axis (fl) and the one or more hinge axes (f2, f3) are parallel to the accommodation portion and, when folded, the one or more hinge axes (f2, f3) are configured to divide the second portion into at least a first support and a second support, wherein the at least one elastic unit (313, 314) is disposed on at least one of the first end and the second end of the accommodation portion and the at least one elastic unit is configured to face the buttress, wherein at least a portion of the at least one elastic unit is configured to interlock with at least a portion of the buttress according to a rotational movement of the buttress, so as to minimize rocking or movement where the second electronic device is supported in the inclined state, and wherein the buttress includes: a first outer face exposed to the outside that includes at least one connection terminal disposed in a central region to be elastically movable; and a second inner face opposite to the first outer face that includes a plurality of first magnets that are mounted at regular intervals along a longitudinal direction to provide a force to minimize a rocking or moving of the buttress relative to the second electronic device, a first outer face exposed to the outside that includes at least one connection terminal disposed in a central region to be elastically movable; and a second inner face opposite to the first outer face that includes a plurality of first magnets that are mounted at regular intervals along a longitudinal direction to provide a force to minimize a rocking or moving of the buttress relative to the second electronic device, wherein the first electronic device includes a metal member corresponding to the plurality of magnets on the accommodation portion.