Usually there is no border control travelling in the Schengen countries, however, you still need to have your passport as a means of identification.
Identity cards from some countries are also suitable (please check with your Ministry of Foreign Affairs before your flight to find out if your identity card is suitable for traveling to selected countries). Border control between some Schengen states is renewed periodically for national security and other reasons.
Schengen countries: Austria, Belgium, Czech Republic, Denmark, Estonia*, Finland, France, Germany, Greece, Hungary, Iceland, Italy, Latvia *, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain , Sweden.
* Please note that Latvian and Estonian authorities continue to require passengers traveling to / from Riga and Tallinn to present a passport or national identity card on arrival / departure.