A controller for a vehicle including at least one motor driving wheels, an inverter driving the motor, and a boosting converter supplying a dc power supply current to the inverter, is provided with a control portion performing rectangular wave control and non-rectangular wave control on the inverter in a switched manner. The control portion has an emergency switching condition for switching control from the rectangular wave control to the non-rectangular wave control, as a determination reference, and when the emergency switching condition is satisfied while the rectangular wave control is being executed (YES at step S5), the control portion instructs the boosting converter to lower target output voltage (S7). Preferably, the control portion determines that the emergency switching condition is satisfied when a q-axis current supplied from the inverter to the motor exceeds a prescribed threshold value.