NEC Semiconductors in Ballivor, Co Meath, is to close with the loss of 350 jobs.
The company made the announcement this evening and is blaming high operating costs for the closure.
The company employed 300 full time and around 50 part time staff. The jobs will be transferred to Singapore, Beijing and Malaysia.
NEC Semiconductors has been based in the small south Meath village for around 30 years and makes semiconductors for use in the automotive industry in Europe.
It said the cost cutting measures were inevitable as part of a global restructuring.
As they left the factory this evening, workers expressed their shock and dismay at the news.