Factory gate prices had a monthly increase of 1.1% in May, according to official figures from the Central Statistics Office.
As a result, prices of products before they reached the consumer showed an annual increase of 2% for that month, compared to an annual decrease of 0.4% to April of this year.
Electronic products had the most significant changes, up 7.8%, while food and chemical prices also showed significant increases.
Meanwhile, the price of petrol had an annual increase of 26% in the year since May 2009.