Is the exosphere the outer layer of the thermshere?

Yes, the exosphere is the outermost layer of Earth's atmosphere, situated above the thermosphere. It extends from about 600 kilometers (373 miles) to 10,000 kilometers (6,200 miles) above sea level. In this region, the atmosphere is extremely thin, and particles are so sparse that they can travel hundreds of kilometers without colliding with one another. The exosphere gradually transitions into outer space.