In the last two decades most information sources both old and new were digitized or prepared directly in digital form. This process allows a better accessibility and visibility of information throughout the world. In order to find useful information easily and quickly, it is important to have a coordinated search engine. The paper deals with the development of a demonstrative digital technical library. The controlled search engine is based on the multilingual illustrated micro-thesaurus in the technical field of mechanisms science according to the librarian indexation rules. Some search possibilities are presented.