An electronic device (201, 400), comprising: at least one sensor; a processor electrically connected to the at least one sensor; a memory electrically connected to the processor; a support structure having one end connected to a boundary of a first area and a second area of a rear surface of the electronic device configured to cover the second area in a closed state by rotating in one direction based on the one end and configured to support the electronic device in various slopes in an open state according to a rotation angle of the support structure; and a speaker disposed in the second area, wherein, when executed, the memory stores instructions that enable the processor to: detect that the support structure is open using the at least one sensor (240, 460); detect a movement of the electronic device using the at least one sensor in a state in which the support structure is open; detect a slope to a reference surface of the electronic device corresponding to a rotation angle of the support structure, using the at least one sensor, when the movement of the electronic device is less than a predetermined threshold value for a predetermined time or more; determine a size of a rear space of the electronic device formed by the second area, the support structure, and the reference surface based on at least a portion of the detected slope; and control an operation of the electronic device based on the size of the rear space, wherein the operation comprises adjusting an output setting value of a sound output through the speaker based on the size of the rear space. at least one sensor; a processor electrically connected to the at least one sensor; a memory electrically connected to the processor; a support structure having one end connected to a boundary of a first area and a second area of a rear surface of the electronic device configured to cover the second area in a closed state by rotating in one direction based on the one end and configured to support the electronic device in various slopes in an open state according to a rotation angle of the support structure; and a speaker disposed in the second area, wherein, when executed, the memory stores instructions that enable the processor to: detect that the support structure is open using the at least one sensor (240, 460); detect a movement of the electronic device using the at least one sensor in a state in which the support structure is open; detect a slope to a reference surface of the electronic device corresponding to a rotation angle of the support structure, using the at least one sensor, when the movement of the electronic device is less than a predetermined threshold value for a predetermined time or more; determine a size of a rear space of the electronic device formed by the second area, the support structure, and the reference surface based on at least a portion of the detected slope; and control an operation of the electronic device based on the size of the rear space, wherein the operation comprises adjusting an output setting value of a sound output through the speaker based on the size of the rear space. detect that the support structure is open using the at least one sensor (240, 460); detect a movement of the electronic device using the at least one sensor in a state in which the support structure is open; detect a slope to a reference surface of the electronic device corresponding to a rotation angle of the support structure, using the at least one sensor, when the movement of the electronic device is less than a predetermined threshold value for a predetermined time or more; determine a size of a rear space of the electronic device formed by the second area, the support structure, and the reference surface based on at least a portion of the detected slope; and control an operation of the electronic device based on the size of the rear space, wherein the operation comprises adjusting an output setting value of a sound output through the speaker based on the size of the rear space.