A device for applying a hair product to sections of hair includes a first part having an open cavity to contain the hair product. The product is applied to the section of hair by contacting the section of hair with the product inside the cavity and moving the device relative to the section of hair. The device also includes a second part having a retention member that is movable relative to the cavity to selectively open and close the cavity. When closed, the retention member keeps the section of hair in contact with the product inside the cavity as the device moves relative to the section of hair. The retention member preferably includes a porous and/or fibrous element that can absorb or in other words be impregnated with the hair product.