A treatment apparatus (1), using a sterilizing substance, for closures (2) for containers, including: a rotating unit (6); a plurality of longitudinal rails (7) able to house the closures (2) arranged by force of gravity, the rails (7) being solidly connected to the rotating unit (6) and being arranged such as to follow a circumferential extension of the rotating unit (6); dispensing apparatus (16) of the sterilizing substance, a variable-height support profile (15) located below the rails (7) and also having a circumferential extension such as to support the lines (8) of closures (2).