An object is to provide a mobile electronic device and an input method that can display soft keys corresponding to each of the characters of different character kinds appropriately even in a state where the display screen of the display unit is used horizontally. In a state where the display screen is used vertically, the control unit splits the display screen into upper and lower sides and displays the plurality of soft keys in the display screen uniformly. In a state where the display screen is used horizontally, the control unit splits the display screen into right and left sides, and displays the first character kind character on one side, and displays the second character kind character on the other side, and displays a plurality of soft keys on either one of the one side or the other side in a right-left direction.