A display device (DD) comprising: a flexible display module (DM); a supporting plate (SPP) disposed under the display module (DM); a plurality of supporting bars (SB) spaced apart from each other in a first direction (DR1), disposed under the display module (DM) and arranged in the first direction (DR1) with the supporting plate (SPP); a supporting film (SFL) disposed between the display module (DM) and the supporting plate (SPP) and between the display module (DM) and the plurality of supporting bars (SB); a first case (CS1) accommodating the display module (DM), the supporting plate (SPP), the supporting film (SFL), and the plurality of supporting bars (SB); and a second case (CS2) which is coupled to the first case (CS1) and configured to move along the first direction (DR1) to be close to or to be far away from the first case (CS1), wherein opposite sides of the plurality of supporting bars (SB) are respectively inserted into first guide grooves (GG1) defined in inner side surfaces of the first case (CS1), which face each other in a second direction (DR2) crossing the first direction (DR1), and the plurality of supporting bars (SB) are arranged to move along the first guide grooves (GG1) when the second case (CS2) moves along the first direction (DR1), wherein a length of the supporting film (SFL) in the second direction (DR2) and a length of the display module (DM) in the second direction (DR2) are less than the length of each of the supporting bars (SB) in the second direction (DR2), such that the display module (DM) and the supporting film (SFL) are not inserted into the first guide grooves (GG1). a flexible display module (DM); a supporting plate (SPP) disposed under the display module (DM); a plurality of supporting bars (SB) spaced apart from each other in a first direction (DR1), disposed under the display module (DM) and arranged in the first direction (DR1) with the supporting plate (SPP); a supporting film (SFL) disposed between the display module (DM) and the supporting plate (SPP) and between the display module (DM) and the plurality of supporting bars (SB); a first case (CS1) accommodating the display module (DM), the supporting plate (SPP), the supporting film (SFL), and the plurality of supporting bars (SB); and a second case (CS2) which is coupled to the first case (CS1) and configured to move along the first direction (DR1) to be close to or to be far away from the first case (CS1), wherein opposite sides of the plurality of supporting bars (SB) are respectively inserted into first guide grooves (GG1) defined in inner side surfaces of the first case (CS1), which face each other in a second direction (DR2) crossing the first direction (DR1), and the plurality of supporting bars (SB) are arranged to move along the first guide grooves (GG1) when the second case (CS2) moves along the first direction (DR1), wherein a length of the supporting film (SFL) in the second direction (DR2) and a length of the display module (DM) in the second direction (DR2) are less than the length of each of the supporting bars (SB) in the second direction (DR2), such that the display module (DM) and the supporting film (SFL) are not inserted into the first guide grooves (GG1). <EOS>