To provide a new laser peening treatment method and a laser absorption powder layer sheet for performing the laser peening treatment.

According to the laser peening treatment method, laser peening treatment is performed by a new method of driving powder or a mixture 13F into the face to be worked in a work 10 by the shock waves of plasma generated upon the irradiation of a laser, thus the production of a product having new material characteristics is made possible. Further, in the case the face to be worked in the work 10 is formed of a metal, when the powder or mixture 13F is driven into the face to be worked in the work 10, the surface part of the work 10 is plastically deformed and metal crystals are fractionated, thus the face to be worked in the work 10 is hardened, and the wear resistance, sliding resistance and corrosion resistance of the face to be worked in the work 10 are remarkably improved.