An electronic device is provided. The electronic device includes a housing including a first housing and a second housing, the second housing being configured to movably engage with the first housing between a retracted position and an extended position, a display assembly coupled to the first housing and the second housing, wherein a size of an area of the display assembly visible from a front side of the housing changes as the second housing moves between the retracted position and the extended position, wherein the display assembly includes (i) an extended portion that is exposed in the extended position and obscured in the retracted position, and (ii) a fixed portion connected to the extended portion, the fixed portion being fixedly exposed, a first case disposed toward one side of the housing, the first case including a case groove, and a structure disposed within the case groove, the structure being disposed toward at least a portion of a display curved area of the display assembly, wherein the structure includes a structure substrate located within the case groove, a support structure disposed toward one side of the structure substrate, and a plurality of actuators at least partially disposed on the structure substrate, the plurality of actuators being configured to move the support structure in a first direction toward the display curved area or in a second direction opposite to the first direction.