An automatic transmission control unit includes a shift-by-wire control circuit that inputs an electrical signal based on a selected range selected by a driver, changes a range changeover member of an automatic transmission using the rotation of a motor to a predetermined position based on the electrical signal, and outputs a signal that drives the motor so as to achieve a travel range; and an automatic transmission control circuit that inputs the electrical signal based on the selected range and a signal based on a vehicle state and outputs a signal for controlling the automatic transmission in order to achieve the travel range, wherein the shift-by-wire control circuit and the automatic transmission control circuit are accommodated in one storage portion.