The bank's decision to leave its key rate at 2.5 percent this month was expected.
The name of this key interest rate has changed over the years.
The bank's move put its key rate at 3.5 percent.
But they held that the key rates might next be cut in September.
The increase was the second in a week, and it brought the key rate to the highest level since the summer of 1985.
It was the first cut in that key rate since August 1986.
West Germany, for example, is expected to raise a key interest rate today.
Germany's central bank raised its two key interest rates to their highest levels since 1948.
He noted that the 3 percent key rate set early this month was "very low by historical standards."
British banks cut key interest rates today by half a percentage point, to 9 percent.