When a patent expires?

Termination of the exclusive rights [in this case patent is concerned] next to cancellation and revocation of the decision of his award, is one of the reasons for termination of exclusive rights in polish ip law.

Under art. 90  (Act of 30 June 2000 on Industrial Property Law), the patent expires due to:
  1. the period for which it was granted,
  2. waiver by the holder of the patent before the Patent Office
  3. failures of payment periodic fees or
  4. permanent loss of use of the invention, due to lack of resources necessary for this biological material that has become unavailable and can not be reproduced on the basis of the description.