Googledoesn't provide an out-of-the-box option to focus searches on the EU, but it is possible to game Google. bluequell on the Google forums assembled a search string to that effect:
Theoretically it's possible to specify more than one country by separating the Country Collection Values with the "|" (pipe) character, so specifying all 28 EU member countries should achieve what you're asking. I've tried this and it appears to work. The URL is fairly long, but you could set it as a bookmark and use it whenever you need an EU-only search. Bear in mind that results will only be returned in the language of your search terms, so searching using English search terms will only produce results from English language webpages. This won't affect any ads which might be included on the search results pages.
I don't know whether Google will ever institute an EU search but, in the meantime, I hope this helps.