A breast tomography apparatus includes a gantry incorporating a radiation source and a radiation detector and a breast insert portion which is provided in the gantry and in which the breast as an imaging target is to be inserted. The breast tomography apparatus detects contact between an object and the gantry by using at least one contact detection sensor arranged on the gantry, and determines the insert condition of the breast into the breast insert portion based on the detection of contact between the object and the gantry by the contact detection sensor.
