1. An information processing apparatus comprising: a display section provided with a screen capable of displaying a content of an application; a user-input processing section for acquiring an instruction input from a user; and a screen-hierarchy control section for managing a screen hierarchical order of each application when contents of a plurality of started applications are displayed in the display section, wherein when one of at least two applications out of a plurality of the applications is set to be a master application and the other of the applications is set to be a slave application, the screen-hierarchy control section disposes and links the slave application at an immediately lower level than that of the master application in the screen hierarchy, and performs screen-hierarchy control such that the master application and the slave application are moved in the screen hierarchy in a state of being linked at the time of updating the screen hierarchy, and when the user inputs an instruction to display the slave application content onto the screen of the display section, the screen-hierarchy control section temporarily releases the linkage between the master and the slave, and sets the slave application content at a highest level of the screen hierarchy.