Demand for Japanese cars has slumped during the global downturn
Japan's factory output has jumped at its fastest rate in more than 50 years, but higher unemployment figures have dampened hope of an early recovery.
Output rose by 5.2% in April from the previous month, the biggest monthly gain since 1953, official figures show.
The much bigger-than-expected rise is the second monthly increase in industrial production in a row.
However, separate figures showing unemployment hitting a five-year high dampened much of the optimism.
The jobless rate hit 5% in April, up from 4.8% in March.
"I'm quite disappointed that the job situation has deteriorated sharply," said Finance Minister Kaoru Yosano.
And some analysts questioned whether the big jump in output was sustainable.
"In the next fiscal year, after the stimulus fades, industrial output may stagnate," said Yasuo Yamamoto at the Mizuho Research Institute.
The conflicting data adds to the mixed messages coming out of the world's second-largest economy.
Earlier this week, official figures showed a surprise trade surplus and an easing in the country's dramatic slump in exports, while last week Japan's central bank upgraded its economic outlook.
However, scepticism remains about the economy's ability to bounce back from its record contraction in the first three months of this year.
"The labour market is bad and prices are weak, pointing to a deflationary trend. Output is not strong enough to boost the jobs market, so people won't feel the economy is recovering," said Mr Yamamoto.