Abstract: An information terminal device includes an input unit that inputs, when a touch operation performed in a detection area that is associated with one of keys of a software keyboard displayed on a screen has been detected, a character associated with the key in the detection area. The information terminal device includes a determining unit that determines, when a modification of a character input by the input unit has been detected, whether the key of the pre-modification character is adjacent to a key of a post-modification character in the layout of the software keyboard. The information terminal device includes a correcting unit that extends, when the determining unit determines that the key of the pre-modification character is adjacent to the key of the post-modification character, the detection area of the key associated with the post-modification character in the arrangement direction of the key that is associated with the pre-modification character.