Container or bottle made of PET or a similar material with incorporated anti-tampering device, comprising a permanent structural inwardly bending in any region of its side wall, which permanent structurally inwardly bending can be reversibly deformed intended for being outwardly bent when the pressure inside the bottle is greater than the atmospheric one and for recovering its original structural inwardly bending when the pressure inside the bottle is again like the atmospheric one, characterised in that a) the said structural inwardly bending forms a region revealing and/or indicating the tampering action having a stable structural deformation corresponding to an inwardly bended profile when the pressure inside the bottle is again like the atmospheric one and a second configuration corresponding to an outwardly bent profile when the inner pressure is greater than the pressure outside said container where said region revealing the tampering action is intended for passing from said second to said first profile when the pressure inside said container decreases from a pressure greater than the atmospheric pressure to a pressure like the atmospheric pressure when the container is perforated or opened; b) the recovery of the first inwardly bent profile of the region indicating or revealing the tampering action is automatic or is caused by an outer mechanical or manual compression in the direction of the deformation of said region indicating and/or revealing the tampering action once the inner pressure is equal to the atmospheric one; c) the region indicating and revealing the tampering action is composed of a region of the container that can be well seen and the inwardly bent profile is shaped like a recess when the container is empty, while once it is filled, put under pressure and sealed in order to be sold, said region revealing the tampering action that had a recess-like shape passes to the opposite outwardly bent profile connecting to the adjacent wall part of the container by finishing it; d) the deformed portion of sections of the structural inwardly bending on circumferences of the bottle has bending radius smaller towards the center than towards their ends. a) the said structural inwardly bending forms a region revealing and/or indicating the tampering action having a stable structural deformation corresponding to an inwardly bended profile when the pressure inside the bottle is again like the atmospheric one and a second configuration corresponding to an outwardly bent profile when the inner pressure is greater than the pressure outside said container where said region revealing the tampering action is intended for passing from said second to said first profile when the pressure inside said container decreases from a pressure greater than the atmospheric pressure to a pressure like the atmospheric pressure when the container is perforated or opened; b) the recovery of the first inwardly bent profile of the region indicating or revealing the tampering action is automatic or is caused by an outer mechanical or manual compression in the direction of the deformation of said region indicating and/or revealing the tampering action once the inner pressure is equal to the atmospheric one; c) the region indicating and revealing the tampering action is composed of a region of the container that can be well seen and the inwardly bent profile is shaped like a recess when the container is empty, while once it is filled, put under pressure and sealed in order to be sold, said region revealing the tampering action that had a recess-like shape passes to the opposite outwardly bent profile connecting to the adjacent wall part of the container by finishing it; d) the deformed portion of sections of the structural inwardly bending on circumferences of the bottle has bending radius smaller towards the center than towards their ends.