The new departure area at Knock International will open on Friday.
Knock International Airport is Ireland's fourth largest international airport and the fastest growing in the country.
In 2003, passenger numbers through the Airport increased by 25% to 250,000 from 199,000 in 2002.
The airport currently operates daily flights to and from Dublin, Stansted, Manchester and Birmingham.
The Minister for Transport, Seamus Brennan, will perform the opening ceremony.