A method for treating textile material (13) to attach dyes, such as synthetic or natural dyes, or to apply bleaches to said textile material (13). The method provides a first step of pre-impregnation of the textile material (13) with an impregnation liquid and a second step of heating the impregnation liquid and the possible dyes or bleaches, through contact of said textile material (13) with at least one heated drum (20), and subsequent vaporization of said impregnation liquid, said textile material (13) being selectively movable on said heated drum (20), subjected to an adjustable pressure higher than atmospheric pressure, a strip (18) being present and exerting on said textile material (13) an adjustable pressure against the heated drum (20).