Pharmaceutical company Pfizer is to invest €145m at its site in Clondalkin in Dublin. The company said it would expand its production and product testing facilities at the plant.
It is thought up to 400 construction jobs will be created during peak construction periods.
The site currently employs approximately 1,100 full time staff. It is one of the largest biotech manufacturing sites in the world and produces two of Pfizer's main drugs, Enbrel and Prevenar 13.
The news has been welcomed by the Taoiseach and the IDA. Taoiseach Enda Kenny said the investment is a further demonstration of the company's continuous commitment to Ireland.
''This investment gives a substantial boost to Ireland's Life Sciences sector and is a vote of confidence in Ireland's attractiveness as a location for bio-pharmaceutical manufacturing,'' commented IDA Ireland's chief executive Barry O'Leary.
Pfizer has about 4,300 workers across eight locations in Cork, Dublin, Kildare and Limerick.