A CT apparatus includes an annular frame that rotates around a subject positioned in a bore, three columns that hold the frame to be rotatable and movable up and down in a vertical, an elevation mechanism that moves up and down the frame, and a rotation mechanism that rotates the frame. A radiation source and a radiation detector are attached to the frame at positions facing each other. The frame has a width smaller than a width of the radiation source and the radiation detector in a height direction over a whole periphery. An imaging controller performs control for operating the elevation mechanism in response to a return instruction from an operator to move the frame to a retreat height position set at a position of a highest point in an elevation range of the frame on an upper end side of the columns. The imaging controller performs control for operating the rotation mechanism in response to the return instruction from the operator to rotate the frame to a position of 60° that is a first rotation position where the radiation source overlaps the columns.