A touch panel input device and a processing execution method eliminates wasteful operations of a user and increases user convenience. If a state determination unit (multiple key press detection unit) detects that multiple operation keys displayed on a touch panel screen were multiply pressed, an operation control unit (first processing execution control unit) controls execution of processing corresponding to any one of the plural operation keys. A waiting unit sets a state, which causes processing to wait for a user to make a selection instruction to select and execute processing corresponding to the other operation key. If the selection instruction is accepted, the operation control unit (second processing execution control unit) controls execution of processing corresponding to the selection instruction so as to select and execute the processing corresponding to the other operation key, following the multiple key press.