A first data section is provided that has a given data actually used when a frictional element is operated under a manual shift mode for providing an engine brake, and a second data section is provided that is actually used when an automatic shift is carried out. A control unit is so configured that when, during a shift from a second speed stage to a first speed stage under the manual shift mode, a mode change from the manual shift mode to the automatic shift mode is instructed, releasing operation of the frictional element is carried out by using the given data of the first dada section.