A tamper evident closure for closing the mouth of a container having a mouth , said tamper evident closure extending along a longitudinal direction (X-X) and comprising: - a threaded outer cap having threads configured to engage with threads associated with the container and rotatable to open the container, : - an inner element longitudinally movable relative to said threaded outer cap and the container from a first position, corresponding to a position prior to first opening, to a second position longitudinally higher than said first position relative to said threaded outer cap , said second position corresponding to the position after first opening, characterized by - cam means configured to cause longitudinal movement of said inner element relative to said threaded outer cap and the container from said first position to said second position when the threaded outer cap is rotated upon first opening, and - locking means configured to lock irreversibly, longitudinally said inner element relative to said threaded outer cap in said second position upon first opening such that said inner element cannot be moved back to the first position, wherein - said threaded outer cap is configured such that a lateral portion of said inner element is visible in said second position, and - upon first opening, said threaded outer cap acts on said inner element such that unscrewing rotation of said threaded outer cap brings about rotation of said inner element . - a threaded outer cap having threads configured to engage with threads associated with the container and rotatable to open the container, : - an inner element longitudinally movable relative to said threaded outer cap and the container from a first position, corresponding to a position prior to first opening, to a second position longitudinally higher than said first position relative to said threaded outer cap , said second position corresponding to the position after first opening, characterized by - cam means configured to cause longitudinal movement of said inner element relative to said threaded outer cap and the container from said first position to said second position when the threaded outer cap is rotated upon first opening, and - locking means configured to lock irreversibly, longitudinally said inner element relative to said threaded outer cap in said second position upon first opening such that said inner element cannot be moved back to the first position, wherein - said threaded outer cap is configured such that a lateral portion of said inner element is visible in said second position, and - upon first opening, said threaded outer cap acts on said inner element such that unscrewing rotation of said threaded outer cap brings about rotation of said inner element . - an inner element longitudinally movable relative to said threaded outer cap and the container from a first position, corresponding to a position prior to first opening, to a second position longitudinally higher than said first position relative to said threaded outer cap , said second position corresponding to the position after first opening, characterized by - cam means configured to cause longitudinal movement of said inner element relative to said threaded outer cap and the container from said first position to said second position when the threaded outer cap is rotated upon first opening, and - locking means configured to lock irreversibly, longitudinally said inner element relative to said threaded outer cap in said second position upon first opening such that said inner element cannot be moved back to the first position, wherein - said threaded outer cap is configured such that a lateral portion of said inner element is visible in said second position, and - upon first opening, said threaded outer cap acts on said inner element such that unscrewing rotation of said threaded outer cap brings about rotation of said inner element . <EOS>