Abstract: A method for controlling displayed contents on a display device upon starting an application is adapted that an operator can start the application while confirming the position and aspect size of a new window corresponding to this application by himself. Upon starting an desired application by a calling point, the calling point is dragged from a calling start point in the pull down menu or the pop-up menu to an arbitrary point on the display screen, thereby defining a window of the desired application as a window with diagonal line formed by a line connecting between said calling start point and a calling cancellation point when the calling state is canceled, and this cancellation of the calling state makes said defined window open to start said desired application.