The Czech Republic is made of the historic lands of Bohemia, Moravia and Silesia, where the first Slavic tribes settled. Today this territory is located in what is geographically called central Europe.
Nonetheless, outside the country, the term Eastern Europe inevitably comes up referring to the Czech Republic. As a matter of fact, Eastern Europe in this case is rather a notion than a geographically precise description as the Czech Republic is still sometimes pigeonholed as being just one of the former East Bloc countries dominated by Eastern doctrines and shut away from Western culture for four decades.
Now, a westernized democracy, the Czechs are not exactly happy about being emotionally placed in the east. They like to stick to geography instead which undoubtedly puts them at the centre of Europe. In fact, less east than for instance Austria.