A display screen management unit is provided which can reduce a screen resource required to switch screens and simultaneously display a pre-transition screen and a post-transition screen. A screen control section requests a screen discard determination section to determine whether or not a currently displayed screen is to be discarded. The screen discard determination section compares currently displayed screen information with switching target screen information, and when the currently displayed screen is completely hidden by the switching target screen, determines that the currently displayed screen is to be discarded. The screen control section discards a screen resource for the screen determined to be discarded, from a screen resource saving section. The screen control section generates a screen resource for the switching target screen, and saves the screen resource into the screen resource saving section. The screen control section causes a display section to display the saved screen resource.