An apparatus for inspecting a fast under investigation moving object on the basis of an image, comprising: - a passage for the moving object to be examined; - a sample-and-imaging device with an accelerator (9) which is intended to emit radiation towards the zone to be examined, moving object, to perform the sampling, a detector which is intended to receive the to be inspected moving object by luminous rays, and an imaging device, which is intended to generate an image from the received the moving object to be inspected by illuminating rays; - a module for counting the under investigation moving objects, comprising a first counter and a second counter to determine retracting the number of the passage to be examined movable objects and outgoing from the passage to be examined movable objects to the number of the to calculate located passage to be examined movable objects, wherein the first counter (2, 3) comprises a first detection unit to determine whether the movable object to be examined is inserted into the passage; - a second detection unit (7) to measure the speed of movement to be inspected moving object in the passage; and - a control unit which is adapted to the second detection unit (7) in response to a received signal from the first detection unit (2, 3) to control over the entry of the to be inspected moving object in the passage to the speed of movement to be examined movable to measure the object, and to set the pulse frequency of the beam from the accelerator (9) in dependence on the measured moving speed, to thereby control a sampling frequency for the investigation of under investigation moving object.