The time required for treatment in different parts is different, and the time required for treatment depends on the size of the treatment area. It takes 5- 10 minutes to treat the beard of lips, 30-40 minutes to treat the hair of legs, and about 90 minutes to treat the hair of legs. It takes a long time to treat the whole back or leg. Because the growth of hair is divided into several cycles, each depilation area should be irradiated several times. After one irradiation, the regenerated hair will be thinner and lighter in color, and the interval between each irradiation will be one to two months, which is better.