Abstract: An apparatus for image diagnosis including an arm rest device having support surfaces for supporting a patient's upheld arms without the use of grasping handles during image diagnosis while the patient is placed in a supine position. The apparatus includes a table on which the patient can be placed, a table support for supporting the table, a detector device for detecting radiation emitted from a radiation source passing through the patient in order to reconstruct cross sectional images of the patient, a gantry for carrying the detector to an investigating position, and the arm rest device. The arm rest device includes a U-shaped base member which has a fixing guide for mounting the arm rest device on the table support and a pair of arm rest pad members which are adjustably placed in the U-shaped base member at appropriate positions for supporting the patient's upheld arms.