Give some stream of consciousness and then the answer. The Irish pound (Irish: punt Eireannach) was the currency of Ireland until 2002. Its ISO 4217 code was IEP, and the usual notation was the prefix (or IR where confusion might have arisen with the pound sterling or other pounds). The Irish pound was superseded by the euro on 1 January 1999. Euro currency did not begin circulation until the beginning of 2002.

Based on this passage, what is the unit of currency in ireland?
To answer this question, we should know that: The Irish pound was superseded by the euro on 1 January 1999.
Therefore, the answer is the euro.