Is there any particular risk (other than the normal investment risk) in investing in an european country other than yours? (i.e. if you are French or Italian and you invest in the German stock market, all in euros).
Assuming your brokerage allows you to invest in companies in other countries the answer is "not really".
Make sure you know and are comfortable with accounting practices and standards in the country that you're investing in. This won't be a problem for most european countries, but will be once you venture past that border.
Make sure there's no laws or regulations that significantly change the risk of investing in a company. I heard but can't confirm that chinese laws actually prevent ownership of chinese companies by foreigners. Make sure to do your research. Again this isn't a problem for european companies when you're european.