A mobile terminal device includes a wireless communication unit that wirelessly communicates with another mobile terminal device different from the mobile terminal device; a fingerprint detection unit that reads a user's fingerprint; and a control unit wherein the control unit performs control to create communication information, send the communication information to the another mobile terminal device, detect first fingerprint information on the user by the fingerprint detection unit, receive second fingerprint information on the user, which is detected by the another mobile terminal device, from the another mobile terminal device that received the communication information, and send information to the another mobile terminal device via the wireless communication unit if the first fingerprint information and the second fingerprint information match.