A hair dryer apparatus comprises two radiating arms (12, 13) shaped to surround the superior and the back part of the hair and pivoted, each with one of the respective ends, into two points, next to each other, of a supporting main structure (11). The radiating arms are rotating in two half-spaces opposite with respect to the median vertical plane of the apparatus, according to oscillating lateral movements of such an extent to allow the emitted heat flow to affect the superior, the back part and side parts of the hair. Means (49) for generating air under pressure are included in the main supporting structure; from this one the air flow is separately conveyed to the radiating arms to maintain the emitted heat flow.