A sliding display device (100, 200, 300, 400), comprising: a housing (120, 120a, 120b, 120c, 220) including a display region between a first edge region and a second edge region, a distance between the first edge region and the second edge region to change as the housing is expanded or contracted in a first direction and a second direction opposite to the first direction; a flexible display panel (140, 240, 340, 440, 540, 640) to slide out from the housing through the first and second edge regions as the housing is expanded and to slide into the housing (120, 120a, 120b, 120c, 220) through the first and second edge regions as the housing (120, 120a, 120b, 120c, 220) is contracted; a first main roller (160, 260, 360, 460) to guide a first panel region of the flexible display panel (140, 240, 340, 440, 540, 640), that is slid into the housing through the first edge region, into an empty space of the housing (120, 120a, 120b, 120c, 220) and to allow the first panel region of the flexible display panel (140, 240, 340, 440, 540, 640) to move along a first moving path in the empty space of the housing (120, 120a, 120b, 120c, 220): and a second main roller (170, 270, 370, 470) to guide a second panel region of the flexible display panel (140, 240, 340, 440, 540, 640), that is slid into the housing (120, 120a, 120b, 120c, 220) through the second edge region, into the empty space of the housing (120, 120a, 120b, 120c, 220), a radius of rotation of the second main roller (170, 270, 370, 470) equal to a radius of rotation of the first main roller (160, 360, 460); the sliding display device (100, 200, 300, 400) characterized by comprising: a further element to allow the second panel region of the flexible display panel (140, 240, 340, 440, 540, 640) to move along a second moving path that does not intersect the first moving path in the empty space of the housing (120, 120a, 120b, 120c, 220), the further element being an assistant roller (180, 290) to assist the second main roller (170, 270, 370, 470) or a support beam (380, 490) to support the second panel region of the flexible display panel (140, 240, 340, 440). a housing (120, 120a, 120b, 120c, 220) including a display region between a first edge region and a second edge region, a distance between the first edge region and the second edge region to change as the housing is expanded or contracted in a first direction and a second direction opposite to the first direction; a flexible display panel (140, 240, 340, 440, 540, 640) to slide out from the housing through the first and second edge regions as the housing is expanded and to slide into the housing (120, 120a, 120b, 120c, 220) through the first and second edge regions as the housing (120, 120a, 120b, 120c, 220) is contracted; a first main roller (160, 260, 360, 460) to guide a first panel region of the flexible display panel (140, 240, 340, 440, 540, 640), that is slid into the housing through the first edge region, into an empty space of the housing (120, 120a, 120b, 120c, 220) and to allow the first panel region of the flexible display panel (140, 240, 340, 440, 540, 640) to move along a first moving path in the empty space of the housing (120, 120a, 120b, 120c, 220): and a second main roller (170, 270, 370, 470) to guide a second panel region of the flexible display panel (140, 240, 340, 440, 540, 640), that is slid into the housing (120, 120a, 120b, 120c, 220) through the second edge region, into the empty space of the housing (120, 120a, 120b, 120c, 220), a radius of rotation of the second main roller (170, 270, 370, 470) equal to a radius of rotation of the first main roller (160, 360, 460); the sliding display device (100, 200, 300, 400) characterized by comprising: a further element to allow the second panel region of the flexible display panel (140, 240, 340, 440, 540, 640) to move along a second moving path that does not intersect the first moving path in the empty space of the housing (120, 120a, 120b, 120c, 220), the further element being an assistant roller (180, 290) to assist the second main roller (170, 270, 370, 470) or a support beam (380, 490) to support the second panel region of the flexible display panel (140, 240, 340, 440).