Abstract: In response to a content display start operation, an initial image is displayed on a display. When a user performs a scroll operation on a touch panel, monitored is whether or not a gap occurs between a first reference position set in an image to be displayed and a second reference position set on a screen associated with the first reference position. When no gap occurs, a display region is moved according to the scroll operation. When the gap occurs, the rate at which the display region moves to adjust the scroll is calculated based on the gap amount at each instant of time. And the displacement value resulting from the moving rate is added to the original position of the display region and then the display region is moved to the position. The displacement value continues to be added until the gap amount becomes zero.