The Markit/JMMA Japan Manufacturing Purchasing Managers Index (PMI) rose to a seasonally adjusted 51.3 in May from 45.7 in April, which was the lowest since April 2009.
The index rose above the 50 threshold that separates expansion from contraction for the first time in three months.
The output component of the PMI index jumped to 51.5 from 35.0 in April, the biggest gain since the data was first compiled in October 2001.
