Abstract: Isotope analysis device comprising a racetrack-shaped ion storage ring, a resonant charge exchange device and a laser photoionization device. Isotope ions to be analyzed are continuously injected into the racetrack in a first orbit and pass through the resonant charge exchange device where they are neutralized and decelerated to produce decelerated isotope particles. Selected isotope particles are then re-ionized by the laser photoionization device, and the resulting selected isotope ions travel around the racetrack in a smaller orbit, while the undesired non-ionized particles exit the storage ring and are separately collected. After several succesively decreasing ion orbits, each isotope of the desired species reaches a detector where it is measured. The device is particularly useful for isotope analysis of strontium and of krypton.