A control apparatus for a voltage converting apparatus configured to realize one-arm drive using only one of a first arm including a first switching element and a second arm including a second switching element by alternatively switching on the first switching element and the second switching element which are connected in series with each other, said control apparatus comprising: a switching control signal generating device configured to generate a switching control signal for changing on and off of the first switching element and a switching control signal for changing on and off of the second switching element; a current detecting device configured to detect a current value of a drive current flowing through the first switching element or the second switching element, at rise timing of the switching control signal, when the one-arm drive is changed between one-arm drive using the first arm and one-arm driving using the second arm; a current estimating device configured to estimate an average value of the drive current by using the detected current value; and a current controlling device configured to control the drive current on the basis of the estimated average value, characterized in that the current estimating device is configured to estimate that the average value of the drive current is a near-zero value which is close to zero if the detected current value is continuously within a predetermined range, and the current controlling device is configured to control the switching control signal generating device to perform near-zero control corresponding to the near-zero value, said control apparatus further comprising: a zero current estimating device configured to estimate that the current value is zero if the detected current value is continuously within the predetermined range; and a zero timing estimating device configured to estimate zero timing at which the average value of the drive current becomes zero, on the basis of the current value estimated as zero and a change in the average value of the drive current, wherein the current controlling device is configured to control the switching control signal generating device such that the average value of the drive current becomes zero at the zero timing. a switching control signal generating device configured to generate a switching control signal for changing on and off of the first switching element and a switching control signal for changing on and off of the second switching element; a current detecting device configured to detect a current value of a drive current flowing through the first switching element or the second switching element, at rise timing of the switching control signal, when the one-arm drive is changed between one-arm drive using the first arm and one-arm driving using the second arm; a current estimating device configured to estimate an average value of the drive current by using the detected current value; and a current controlling device configured to control the drive current on the basis of the estimated average value, characterized in that the current estimating device is configured to estimate that the average value of the drive current is a near-zero value which is close to zero if the detected current value is continuously within a predetermined range, and the current controlling device is configured to control the switching control signal generating device to perform near-zero control corresponding to the near-zero value, said control apparatus further comprising: a zero current estimating device configured to estimate that the current value is zero if the detected current value is continuously within the predetermined range; and a zero timing estimating device configured to estimate zero timing at which the average value of the drive current becomes zero, on the basis of the current value estimated as zero and a change in the average value of the drive current, wherein the current controlling device is configured to control the switching control signal generating device such that the average value of the drive current becomes zero at the zero timing. a zero current estimating device configured to estimate that the current value is zero if the detected current value is continuously within the predetermined range; and a zero timing estimating device configured to estimate zero timing at which the average value of the drive current becomes zero, on the basis of the current value estimated as zero and a change in the average value of the drive current, wherein the current controlling device is configured to control the switching control signal generating device such that the average value of the drive current becomes zero at the zero timing.