The ECB, whose Governing Council is meeting in Bratislava, also cut the interest rate on its marginal lending facility, the amount it charges for one-day loans, by 0.50 percent to 1 percent.
The central bank left the interest rate on its deposit facility at 0 percent.
Financial markets and most analysts expected the ECB to cut the benchmark rate to spur lending and stimulate the weak Eurozone economy.
Some analysts, however, questioned whether a rate cut would do anything to expand lending to small- and mid-sized businesses in the Eurozone's peripheral countries.
Access to credit by small- and mid-sized businesses varies greatly among the different countries in the Eurozone, a recent ECB survey found.
Central banks around the world have been pumping liquidity into their economies in an effort to ramp up growth in the wake of the worst economic downturn since the Great Depression.
The US Federal Reserve has kept short-term interest rates near zero and implemented an aggressive monetary stimulus program pegged to unemployment and inflation targets.
The Bank of Japan has embarked on a program of monetary easing and additional bond purchases to push down interest rates and spark consumer spending.