An electronic device comprising: a guide housing; a slide housing slidably coupled to the guide housing, wherein the slide housing includes an inner plate having a first face that faces an outside of the electronic device and a second face that faces away from the first face, and a first opening formed to penetrate the first face and the second face; a flexible display (303, 603, 1003, 1603) mounted on the first face, wherein the display (303, 603, 1003, 1603) includes: a substantially transparent window (637, 1037, 1637a) including a flexible area forming an outer face of the display (303, 603, 1003, 1603), a light-emitting layer (631, 1031, 1631) disposed under the window (637, 1037, 1637a), a substantially opaque protective layer (639, 1039, 1639) disposed under the light-emitting layer (631, 1037, 1637a), and a second opening (671, 1071, 1671) formed in the protective layer (639, 1039, 1639) and at least partially overlapping the first opening in a vertical direction, wherein a first transparent area (631a, 1031a) corresponding to the second opening (671, 1071) is formed in the light-emitting layer (631, 1031, 1631); a transparent polymeric material filling at least a portion of the second opening (671, 1071); and an image sensor (607, 1007, 1607) at least partially accommodated in the slide housing and at least partially aligned with the first opening under the inner plate. a guide housing; a slide housing slidably coupled to the guide housing, wherein the slide housing includes an inner plate having a first face that faces an outside of the electronic device and a second face that faces away from the first face, and a first opening formed to penetrate the first face and the second face; a flexible display (303, 603, 1003, 1603) mounted on the first face, wherein the display (303, 603, 1003, 1603) includes: a substantially transparent window (637, 1037, 1637a) including a flexible area forming an outer face of the display (303, 603, 1003, 1603), a light-emitting layer (631, 1031, 1631) disposed under the window (637, 1037, 1637a), a substantially opaque protective layer (639, 1039, 1639) disposed under the light-emitting layer (631, 1037, 1637a), and a second opening (671, 1071, 1671) formed in the protective layer (639, 1039, 1639) and at least partially overlapping the first opening in a vertical direction, wherein a first transparent area (631a, 1031a) corresponding to the second opening (671, 1071) is formed in the light-emitting layer (631, 1031, 1631); a substantially transparent window (637, 1037, 1637a) including a flexible area forming an outer face of the display (303, 603, 1003, 1603), a light-emitting layer (631, 1031, 1631) disposed under the window (637, 1037, 1637a), a substantially opaque protective layer (639, 1039, 1639) disposed under the light-emitting layer (631, 1037, 1637a), and a second opening (671, 1071, 1671) formed in the protective layer (639, 1039, 1639) and at least partially overlapping the first opening in a vertical direction, wherein a first transparent area (631a, 1031a) corresponding to the second opening (671, 1071) is formed in the light-emitting layer (631, 1031, 1631); a transparent polymeric material filling at least a portion of the second opening (671, 1071); and an image sensor (607, 1007, 1607) at least partially accommodated in the slide housing and at least partially aligned with the first opening under the inner plate.