Abstract: A face mask unit for protection against contaminants, for example in particles, comprises a face mask with a body having lateral inhalation filters inserted in seats of this body, the body cooperating with hooking means for fastening to a support element for supporting the mask on the face, and an exhalation valve for the exhaled air. An additional filtering member is provided, which is adapted to be arranged on the mask and bearing at least one filtering element, said additional filtering member being fixed to the mask and being arranged a short distance from it so as to create a space between the body of the mask and the filtering element, this space allowing air to flow in to the lateral inhalation filters unimpeded and also creating a void for the exhaled air from the exhalation valve to flow into before passing through said filtering element.