The seasonally adjusted unemployment rate hit 4.7 percent in October, up 0.1 percentage point from the previous month and the first rise in three months, the government said Tuesday.
The number of jobless people fell 320,000 from a year earlier to 3.11 million in the reporting month, down for the 17th consecutive month, the Internal Affairs and Communications Ministry said in a preliminary report.
The ministry left unchanged its assessment that employment conditions are continuing to improve, citing an increase in the number of jobholders and a fall in the number of unemployed from a year earlier.
"But we need to closely monitor the employment trend," due to the October rise in the unemployment rate, a ministry official said.
Some private-sector economists are pessimistic about the outlook for employment as the pace of Japan's economic growth is expected to slow.
Since companies are stepping up production adjustments in line with the slowdown in the economic recovery, this means the improvement in employment conditions is already over, said Osamu Tanaka, an economist at Morgan Stanley Japan Ltd.
"It is now only a matter of time for the jobless rate to return to above 5 percent," Tanaka said.
Japan's unemployment rate has been in the 4 percent range since March, after hitting 5 percent in January and February.
In October, the jobless rate for men was 4.8 percent, unchanged from September, and that for women was 4.5 percent, up 0.3 point.
The rise in the unemployment rate for women might be attributable to typhoons in the reporting month, which adversely affected employment in the wholesale and hotel industries, according to the official.
The number of people with jobs climbed 150,000 to 63.52 million in October, rising for the third straight month, the ministry said.