The BOJ board voted unanimously to leave its unsecured overnight call loan rate unchanged at 0.10%.
Meanwhile, the BOJ maintained its overall economic assessment for August, saying Japan's economic conditions "have stopped worsening" due to a pickup in exports and production. The central bank held to its prediction that the economy will start recovering from the latter half of fiscal 2009, which ends in March.
But the bank took a cautious stance on recent falls in consumer prices, noting that the year-on-year rate of decline in the core CPI has accelerated.
In recent months, the perception has grown that Japan's economy hit bottom earlier this year and is recovering quickly as a pickup in external demand boosts exports, helping industrial production bounce back.
But the jobless rate rose to 5.4% in June, its highest level since June 2003 and just shy of its post-war high of 5.5%.
At its July meeting, the policy board extended some of the temporary liquidity measures, such as outright purchases of commercial paper and corporate bonds, through Dec. 31. The programs were due to expire Sept. 30.
The market also is watching for any indication from Shirakawa that the bank will boost its outright purchases of Japanese government bonds, as expectations grow for a rise in long-term yields as the government's fiscal position deteriorates.