From the website:
The Passport Office, which is part of the Department of Foreign Affairs, issues passports to Irish citizens.
All Irish citizens are entitled to apply for an Irish passport. Services are provided by the Passport Offices in Dublin and Cork and by Irish Diplomatic and Consular Missions overseas.
Passports are required for travel to all countries except the United Kingdom. (However, you should note that some airlines now require photo-ID for flights to the UK). With the exception of travel to the U.K., Irish citizens require a valid passport for travel to all other destinations in the E.U.
For more information: http://www.dfa.ie
