In April annual inflation stood at 3.3 percent, Eurostat said.
For the 17-member eurozone, the countries that use the euro as currency, inflation on a 12-month basis also dropped one tick from 2.8 percent in April to 2.7 percent in May.
A year earlier in May, the eurozone's annual inflation rate was 1.7 percent. In the European Union in May 2010, the inflation rate was 2.1 percent on an annual basis.
In May, the lowest inflation rate was 1.2 percent, posted by Ireland. In Sweden, the rate was 1.7 percent, followed by the Czech Republic with a 2 percent rate.
The highest inflation rate was 8.5 percent posted by Romania, followed by Greece, at 4.8 percent and Estonia at 4.5 percent.