A device for cosmetic treatment of human keratin materials, including: a handpiece that includes an electrical assembly, and an application member that is fixed to the handpiece and defines an application surface, the application surface having an area of between 50 and 200 mm2, or between 70 and 150 mm2, and the handpiece is configured to generate a thermal amplitude of greater than or equal to 5° C. between the keratin materials and the application surface for a duration of at least 5 minutes, or a thermal amplitude of greater than or equal to 20° C. for a duration of at least 5 minutes.
