A mobile terminal device that executes a function setting operation is disclosed. When a memory card that stores various file types is inserted into the mobile terminal device, a decision processing portion reads identification information of the memory card and compares the identification information with stored identification information in a storing portion. If the read identification information and the stored identification information coincide, a function setting controlling portion executes a resetting of a display or of a sound function of the mobile terminal device by using the various file types stored in the memory card.