An automatic transmission control device implements a downshift by disengagement of a clutch that is engaged in a gear position before the downshift. It is determined whether an engine state is in a predetermined region in which a change of an engine torque per a change of an accelerator pedal opening is smaller than that in another region, and the engine torque is within a predetermined range, and an engine rotational speed is within a predetermined range. It is determined whether an operating state is in a predetermined state of accelerator operation in which the accelerator pedal opening is larger than a predetermined value, and an accelerator pedal opening change rate has an absolute value smaller than a predetermined value. The downshift is inhibited in response to determination that the engine state is in the predetermined region and the operating state is in the predetermined state of accelerator operation.