A display device (9, 100) comprising: display means (12, 91) for displaying display information in each of a plurality of display areas; operation means (92, 120) for detecting a position of an action performed on a display surface, the display information being displayed on the display surface in the display means (12, 91); and control means (14, 93) for performing control so that, when a movement of the action position detected by the operation means (92, 120) from the position on the display information is detected, the display information is displayed in another display area located in a direction of the movement of the action position, wherein the control means (14, 93) performs control so that a non-displayed part of the display information which has been moved in the another display area is displayed in the original display area, and characterised in that: the control means (14, 93) switches a display direction of the display information between a vertical direction and a horizontal direction according to a state of a non-displayed part of the display information in a state where the display information is displayed in an extended display area obtained by combining the another display area and the original display area, and when a direction in which there is a non-displayed part of the display information is one of the vertical and horizontal directions and a direction in which a size of the extended display area is larger is the other of the vertical and horizontal directions, hence when these directions are different from each other, the control means (14, 93) switches the display direction of the display information. display means (12, 91) for displaying display information in each of a plurality of display areas; operation means (92, 120) for detecting a position of an action performed on a display surface, the display information being displayed on the display surface in the display means (12, 91); and control means (14, 93) for performing control so that, when a movement of the action position detected by the operation means (92, 120) from the position on the display information is detected, the display information is displayed in another display area located in a direction of the movement of the action position, wherein the control means (14, 93) performs control so that a non-displayed part of the display information which has been moved in the another display area is displayed in the original display area, and characterised in that: the control means (14, 93) switches a display direction of the display information between a vertical direction and a horizontal direction according to a state of a non-displayed part of the display information in a state where the display information is displayed in an extended display area obtained by combining the another display area and the original display area, and when a direction in which there is a non-displayed part of the display information is one of the vertical and horizontal directions and a direction in which a size of the extended display area is larger is the other of the vertical and horizontal directions, hence when these directions are different from each other, the control means (14, 93) switches the display direction of the display information. the control means (14, 93) switches a display direction of the display information between a vertical direction and a horizontal direction according to a state of a non-displayed part of the display information in a state where the display information is displayed in an extended display area obtained by combining the another display area and the original display area, and when a direction in which there is a non-displayed part of the display information is one of the vertical and horizontal directions and a direction in which a size of the extended display area is larger is the other of the vertical and horizontal directions, hence when these directions are different from each other, the control means (14, 93) switches the display direction of the display information.