[PROBLEMS] To provide a multimode portable terminal capable of variously switching over the mode of a network connection according to various needs such as high-quality and high-speed data communication or inexpensive data communication, and a mode switch-over method. [MEANS FOR SOLVING THE PROBLEMS] A multimode portable terminal capable to any one of a plurality of radio communication networks with different standards includes a mode selecting device 51 for presetting mode selection information by input of the user, a network judging device 52 for judging which area of the radio communication networks the multimode portable terminal is present based on presence of control signals peculiar to each radio communication network, and a network selecting device 53 for selecting one of the radio communication networks in whose area the multimode portable terminal is present in the order of priority according to the mode selection information.