Producer prices in Japan were up 0.7 percent on month in May, the Bank of Japan said on Wednesday.
That exceeded expectations for an increase of 0.4 percent and was up from the upwardly revised 0.5 percent gain in April (originally 0.3 percent).
On a yearly basis, producer prices climbed 2.4 percent - again topping forecasts for 2.0 percent and accelerating from the upwardly revised 1.1 percent gain in the previous month (originally 0.9 percent).
The export price index rose 0.1 percent on month, the bank said, while the import price index rose 0.9 percent.