A screen display apparatus includes an operation information reception unit that receives operation information regarding an inclination direction and an inclination angle of a joystick from the joystick, and a screen controller that performs a scroll process for scrolling a screen and a zoom process for zooming based on the operation information. The screen controller scrolls the screen according to the inclination direction and the inclination angle of the joystick, and continues a zoom-out process for zooming-out of the screen based on a detection of the inclination angle that is greater than a predetermined angle for a predetermined period until detecting the inclination angle of the joystick to be equal to or smaller than the predetermined angle or until zooming out to a predetermined minimum zoom rate.