Abstract: An apparatus for protecting closed spaces from flooding or contaminations comprising: a moveable closing element (100) for spaces associated to a corresponding fixed element (101) and adapted to engage therewith during the step of closing; an appropriate peripheral seal (10) with an internal section either hollow or formed by porous material and positioned at the gap existing, in closing position, between said moveable element (100) and the corresponding fixed element (101); at least one transducer element (11), associated to said moveable closing element, adapted to measure the value of one or more physical-chemical parameters; inflation means (13) adapted to modulate the pressure of the fluid contained in the cavity or in the porosity of said seal (10); a control module (12), associated to said at least one transducer element (11) and adapted to drive said inflation means (13).