A portable radio information terminal capable of operating at a plurality of phases to execute different functions. The terminal has a transition-request-input detecting section that detects an input signal generated by an input device in the course of an operation carried out within any current phase of the same plurality of phases to request an inter-phase transition, an inter-phase transition section that suspends the operation carried out at the current phase and executes a transition from the current phase to another phase determined by a result of detection output by the transition-request-input detecting section, and a phase-processing executing section for calling and displaying a screen of the phase transitioned to.