PURPOSE: To shorten a total data collecting time, by contriving the relation between the revolution of a rotary type radiating position detector and the rotation of the collimator of a rotary type radiation position detector.

CONSTITUTION: When a collimator 5 is continuously rotated and the longitudinal direction of a slit approaches so as to become parallel to the track P of the revolution of a radiating position detector 1 viewed from a subject 20 to form an angle θ, said radiating position detector 1 begins to revolve at a unit angle and the longitudinal direction of the slit becomes parallel to the track P during revolution and, when the angle comes to +θ, the revolution is stopped. The angle θ is set to about 15°. The synchronous relation of the rotation of the collimator 5 and the revolution of the radiating position detector 1 controls the rotation of a rotary frame 3 while sending the signal of the rotary angle from the rotation control apparatus 9 of the collimator 5 to a rotary drive apparatus 4. By this mechanism, data collection can be continuously performed and a total data collection time can be shortened.