An X-ray CT apparatus comprises a gantry including an X-ray generator in a rotor, and processing circuitry configured to control rotation of the rotor during a first scan such that a value related to first rotational speed serving as rotational speed of the rotor at a time when the first scan is finished is brought close to a setting value related to second rotational speed serving as rotational speed of the rotor in a second scan, with respect to the first scan and the second scan performed after the first scan is performed.
