According to one embodiment, there is provided an X-ray CT apparatus which comprises high voltage generation processing circuitry configured to selectively generate a first voltage and a second voltage higher than the first tube voltage a first filter formed from a material having substantially the same atomic number as that of a contrast material to be administered to an object and configured to perform radiation quality adjustment a second filter formed from a material different from the contrast material and configured to perform radiation quality adjustment a filter switching mechanism configured to switch between the first filter and the second filter to be interposed between a X-ray tube and the object and control processing circuitry configured to control the high voltage generation unit and the filter switching mechanism to synchronize switching between the first voltage and the second voltage with switching between the first filter and the second filter.
