A mammographic apparatus for taking an image of a breast by detecting an X-ray radiated from an X-ray tube and transmitted a breast of a subject by means of an X-ray detector. The mammographic apparatus includes a column, a first support frame arranged, for rotation about a rotary axis, on the column and supporting the X-ray tube, a second support frame arranged, for rotation about the rotary axis, on the column and supporting the X-ray detector, and a mechanism for selectively switching over between a first mode that the second support frame is rotated by a rotation force of the first support frame and a second mode that the first support frame is rotated independently of the second support frame.