Dublin Airport's €600m Terminal 2 has opened with the first flight arriving just after 11am.
The first Aer Lingus flight to arrive at the terminal came from Manchester and got a Fire Brigade escort from the runway to the new building.
Taoiseach Brian Cowen opened the terminal this morning saying he is 'delighted that Aer Lingus will be the anchor tenant' at T2 with passengers 'set to enjoy the new state of the art facilities' there.
Mr Cowen said that the Government has set the goal of increasing tourist numbers to 8m by 2015 and the new terminal 'will be part of that drive to improve international access and boost visitor numbers'.
While the first official flight arrived today, airlines that are using the new terminal will begin transferring their services to the facility from next Tuesday.
It will not become fully operational until the beginning of next year.
Aer Lingus has advised all departing passengers and people collecting arriving passengers to report to Terminal 1 until further notice.
The transfer of transatlantic flights to Terminal 2 has been delayed as the US customs and border protection service will not be operational there until January.
The new terminal has been built at a cost of over €600m and has the capacity to cater for up to 15m passengers.
Mr Cowen said the investment is 'a commitment that will stand the test of time'.
Ryanair has criticised the project, saying it is not needed.
Chief Executive Michael O'Leary says the terminal was yet more evidence of the collapse in Irish tourism.
Mr O'Leary was dressed in a funeral suit and Ryanair staff carried a tricolour bedecked coffin from the airline's headquarters at Dublin Airport to Terminal 2 this morning bearing the words 'Irish Tourism RIP'.