The Tyrone Crystal factory in Dungannon, Co Tyrone is to close with the loss of 31 jobs.
The company has said it will be entering "an orderly winding down period of its factory processes".
A change in taste and recession are attributing factors for the downturn in sales.
The company, which was established 40 years ago as a co-operative, has become synonymous with Northern Ireland and is a key tourist attraction in Dungannon. Some of the production staff have spent their working lives in the plant.
Fermanagh and South Tyrone MP Michelle Gildernew said she believed the management at the plant had done all in their power to keep the plant open.
"The writing may have been on the wall for some time at Tyrone," she said, referring to the closure of Waterford Crystal.
"It is the end of an era for Tyrone and for Dungannon and probably also for the production of crystal in Ireland as well."