A display device comprising a flexible display, the device comprising: a housing; a roller disposed in the housing; a flexible display which is lowered to the housing or lifted above the housing, and configured to be rolled around the roller when the flexible display is lowered and comprising a display panel, and a display cover disposed on a back surface of the display panel; an upper assembly (48, 49) coupled to an upper portion of the flexible display, the upper assembly including a connecting bar disposed to be elongated on the upper portion of the display cover; and a lift assembly connected to the connecting bar and comprising: a rotation mechanism including a motor and a power transmission member, and a controller which controls the rotation mechanism, a pair of arms (911, 912) and an arm joint connected to each of the pair or arms, the pair of arms including a first arm rotatably coupled to the connecting bar, a second arm coupled to the first arm and configured to be pivotably raised in response to an operation of the motor, so that when the motor is driven, the flexible display is unwound from the roller or wound around the roller, a sensing module connected to the second arm and configured to detect an angle of the second arm based on a rotation of the second arm, and configured to transmit a sensing value to the controller through a signal line connecting the sensing module and the controller. a housing; a roller disposed in the housing; a flexible display which is lowered to the housing or lifted above the housing, and configured to be rolled around the roller when the flexible display is lowered and comprising a display panel, and a display cover disposed on a back surface of the display panel; an upper assembly (48, 49) coupled to an upper portion of the flexible display, the upper assembly including a connecting bar disposed to be elongated on the upper portion of the display cover; and a lift assembly connected to the connecting bar and comprising: a rotation mechanism including a motor and a power transmission member, and a controller which controls the rotation mechanism, a pair of arms (911, 912) and an arm joint connected to each of the pair or arms, the pair of arms including a first arm rotatably coupled to the connecting bar, a second arm coupled to the first arm and configured to be pivotably raised in response to an operation of the motor, so that when the motor is driven, the flexible display is unwound from the roller or wound around the roller, a sensing module connected to the second arm and configured to detect an angle of the second arm based on a rotation of the second arm, and configured to transmit a sensing value to the controller through a signal line connecting the sensing module and the controller. a rotation mechanism including a motor and a power transmission member, and a controller which controls the rotation mechanism, a pair of arms (911, 912) and an arm joint connected to each of the pair or arms, the pair of arms including a first arm rotatably coupled to the connecting bar, a second arm coupled to the first arm and configured to be pivotably raised in response to an operation of the motor, so that when the motor is driven, the flexible display is unwound from the roller or wound around the roller, a sensing module connected to the second arm and configured to detect an angle of the second arm based on a rotation of the second arm, and configured to transmit a sensing value to the controller through a signal line connecting the sensing module and the controller.