It has been at that level for the past two years, despite weak growth in the euro zone economy.
ECB President Jean-Claude Trichet says the decision to leave the rate alone was unanimous. He said bank governors agreed the current rate is appropriate.
But the ECB is facing growing pressure to cut interest rates to stimulate European economies. Mr. Trichet said before the vote that cutting rates would hamper the economic stability of the region.
The ECB is the chief monetary authority for the 12 countries that use the euro.
Some information for this report provided by AP.