A mobile terminal device includes a communication portion, a display plane, a first storage portion, and a control portion which controls to display a standby screen on the display plane during a standby operation of the communication portion. When the communication portion receives a communication message, the control portion controls to store the communication message in the first storage portion, then extracts at least a part of any of sender information, subject information, or text information in the communication message, forms an electronic tag in which a character string based on the extracted information is indicated, and controls the display portion to display the electronic tag on the standby screen.