Espacenet is a free database developed by the European Patent Office and the member states of the European Patent Organisation. Go to Espacenet by clicking here.
Espacenet was put online in 1998 and holds documents on patents from over 90 countries. Information on patents from 1836 until now is included. In the database, documents can be translated into another language, so you can easily read the information.
Tutorials
For more information and tutorials on this database, go to this website.