A medical X-ray CT photography apparatus body includes a turning arm that supports an X-ray generator and an X-ray detector while the X-ray generator and the X-ray detector are opposed to each other with the subject interposed therebetween, a bracket part that fixedly supports an axial center position of a turning shaft provided in the turning arm, and a support drive part that turns the turning arm about the turning shaft with respect to the bracket part. The medical X-ray CT photography apparatus body also includes a subject chair on which the subject sits, a chair moving mechanism that linearly moves the subject chair in a front-back direction (Y-axis direction) of the subject, and a main-body controller that performs the panoramic X-ray photography by controlling the chair moving mechanism and the support drive part in conjunction with each other.