Dr. rer. nat. Jens Hammer

German Patent Attorney, European Patent Attorney

hammer@grunecker.de     S/MIME

+49 (0) 89 21 23 50

Office: Munich

Languages: German, English


Jens Hammer’s practice focuses on patent law, particularly in chemistry. For decades, he has represented leading companies, SMEs, and start-ups worldwide before the relevant offices (DPMA, EPO) and courts. He is regularly involved in complex opposition and opposition appeal proceedings and appears before the European Patent Office’s opposition divisions and boards of appeal.

His practice specialises in handling complex applications at the interface between chemistry, process control, and process engineering, which require legal advice with access to different technical fields. Examples include the latest developments in electromobility, components and materials for batteries and solar cells, and large-scale plants in the fields of green hydrogen and green ammonia.

Jens also advises his clients on portfolio management, inventor law issues, strategies for obtaining efficient cross-border patent protection and assessing IP-related problems in company takeovers.

Even though it has been many years since his last dunk, Jens is still passionate about basketball, albeit mainly from a spectator’s perspective.


  • Patent Law
  • Patent Infringement
  • Due Dilligence

Technical fields

  • Chemistry
  • Nano Technology
  • Battery Technology
  • Process Engineering


  • University of Hamburg: Diploma in Chemistry, 1992
  • PhD in Chemistry (Institute of Macromolecular and Technical Chemistry), 1995
  • EU Fellow at the Institute of Inorganic Chemistry (Carbon Nanotubes), Oxford University, 1996
  • Licensed patent attorney, 2000
  • European Trademark and Design Attorney, 2000
  • European Patent Attorney, 2001
  • Partner at Grünecker, since 2008


„Protecting and Enforcing Life Science Inventions in Europe”, Co-author
C.H.Beck, Hart, Nomos, Helbing Lichtenhahn, 2015

Awards & Rankings

Recommended; Patent Filing – Germany
“high quality in chemical and pharma patents combined with pragmatic advice”, competitor, JUVE, 2023

Core Attorney – Prosecution and official Proceedings (Tier 1)
“The key figures in the team include (…) Jens Hammer (Chemistry and Pharmacy).”, Legal500, 2023