A controller including an electronic control unit, the electronic control unit is configured to determine at least one of whether a first absolute value is at least equal to a first threshold and whether a second absolute value is at least equal to a second threshold. When the electronic control unit determines that at least one of the first absolute value and the second absolute value is at least equal to the corresponding threshold, torque capacity of an automatic clutch is controlled such that the automatic clutch is brought into a slipping state. The first absolute value is an absolute value of rotational acceleration of an input shaft of a transmission, and the second absolute value is an absolute value of rotational acceleration of drive wheels.