A PET gantry and a CT gantry are placed in parallel such that the CT gantry becomes remoter to a common examination couch having a movable couch table top board mounted with a subject person and the CT gantry is made to be movable. The gantries are controlled by a control portion in a console. At first, the CT gantry is moved in a left direction to separate from the PET gantry so that whole body CT scan is carried out for the subject person in a direction from the leg portion to the head portion. Successively, the subject person is passed through a tunnel portion from the leg portion to the head portion by moving the couch table top board in a right direction in a state of considerably separating the CT gantry from the PET gantry to thereby carry out whole body PET scan.