To provide an ejection tester keeping excessive pressure from acting on an acceleration tube even where a sabot and a flying object are separated from each other by a sabot stopper, and preventing the sabot from scattering.

This ejection tester 1 includes the acceleration tube 4 for accelerating the sabot 3 that holds the flying object 2 by using acceleration energy, a vacuum chamber 6 housing a front end of the acceleration tube 4 while housing a target 5 with which the flying object 2 accelerated in the acceleration tube 4 is made collide, and the sabot stopper 7 provided in the vacuum chamber 6 and used for receiving the accelerated sabot 3 to separate the flying object 2 from the sabot 3 while making only the flying object 2 collide with the target 5. In the ejection tester 1, the sabot stopper 7 is disposed apart from the acceleration tube 4, and a slidable positioning/scattering-preventing cylinder 29 is provided between the acceleration tube 4 and the sabot stopper 7 for coupling the two while positioning the acceleration tube 4 to the sabot stopper 7.