Not patentable are for example discoveries, mathematical methods, rules for performing mental acts (e.g. rules of a game or use instructions), computer programs as such, i.e. if they do not contain a technical component or the solution to a technical problem, aesthetic creations and medical treatments.

A patent application effective for Germany can either be filed at the German Patent and Trademark Office as a national German Patent Application or at the European Patent Office as a European Patent Application in accordance with the European Patent Convention (EPC).

Before a patent is granted, the patent office in charge of the patent application examines the same for the aforementioned criteria, namely novelty, inventive activity and industrial applicability. Only after the successful conclusion of said examination proceedings will a patent be granted.

A patent granted by the German Patent and Trademark Office is effective in Germany only.

A European patent granted by the European Patent Office does not automatically take effect in all EPC states. In the course of the application proceedings the states for which patent protection is sought have to be designated first. After the patent is granted, the European Patent then has to be validated in said designated states. In other words, the European Patent Application merely combines the application and examination proceedings for the designated states. After the grant, the European Patent is separated into a bundle of national patents.

Another possibility of filing a patent application is the filing of an international patent application, with a central application process and an international search being carried out. Preliminary international examination proceedings may follow. The international patent application will be separated into national patent applications after the international phase is concluded.