A diffuser includes an air inlet for receiving an airflow from a hair dryer, and a grille with a plurality of air outlets for emitting at least part of the airflow. Each of the air outlets has substantially the same shape. The plurality of air outlets includes a first set of air outlets located in a first region of the grille, and a second set of air outlets located in a second region of the grille. The grille further includes at least one third region, located between the first region and the second region, which is substantially devoid of these air outlets.