A method for treating a hair shape comprising the steps of: subjecting hair to softening treatment by applying or spraying a softening agent or applying a hair-treating agent, and giving vibration of predetermined frequency of not exceeding 20 KHz being lower than a frequency of ultrasonic wave to hair to give a desired shape to hair. It is possible to cause cutting of cystine linkage, salt linkage, hydrogen linkage or the like in keratin of the hair, which was hard to be done in a conventional permanent treatment, to every portion of hairs by making an effect of the first liquid (softening agent) being sufficiently exhibited in permanent treatment.