Inflation in Germany, slowed to 1.9% in May, the first time since December 2010 that it has been below the key level of 2.0%.
Inflation in the euro zone's biggest economy had stood at 2.1% the previous month and falling fuel prices were the main reason for the slowdown, the national statistics office Destatis said in a statement.
On a monthly basis, the cost of living in Germany declined by 0.2% in May from April, the statisticians calculated.
Using the Harmonised Index of Consumer Prices, the ECB's inflation yardstick, the cost of living in Germany rose by 2.1% on a 12-month basis in May, fractionally slower than the 2.2% recorded in April.
The ECB defines price stability as increases in the HICP of close to but just below 2.0%.
Preliminary inflation data are calculated using consumer price data for six of Germany's 16 federal states.
Final data, based on statistics for all 16 states, are scheduled to be published on June 13.