A control apparatus sets an upper limit guard value to a base value when the MG provides torque assist to thereby limit the command value for the MG. Then, the control apparatus limits the command value for the MG using the upper limit guard value to limit the output of the MG. If an accelerator opening or the change rate thereof is not less than a predetermined value, the control apparatus corrects the upper limit guard value. The correction is made such that the larger accelerator opening or a larger change rate thereof causes the upper limit guard value to be larger to accomplish higher output. Similarly, if the SOC of the battery is not less than a predetermined value, the control apparatus corrects the upper limit guard value. If the engine speed is not less than a predetermined value, the control apparatus corrects the upper limit guard value.