The increase of 36,100 took the new total to 2,756,500, the highest level since January 2000. The monthly increase of 1.3 percent was the highest since October 2009.
Employment minister Xavier Bertrand told BFM TV the figures were "bad" but that he was "optimistic for the future because jobs are being created."
Eric Heyer, an economist with the French Economic Observatory, told newspaper 20 Minutes the figures had been expected.
"The pattern is not going to improve," he said. He predicted that the unemployment rate would reach 9.6 percent by the end of the year.
Unemployment increased for all age groups, with people aged 50 and over being hardest hit.
For those out of work for more than a year, the figure is now 1.6 million, up 9.2 percent on last year.
"The explosion in long-term unemployment is very worrying," said Eric Heyer. "The more time that passes, the more difficult it is to find work."
For the Socialist party, the rise represented "the complete failure of Nicolas Sarkozy's policies."
In a statement on Thursday, the party's employment spokesman, Alain Vidalies, said the statistics underlined "the gravity of the economic and political mistakes of these last few years."