 Chievo was slipped from 4th (post-trail) or 7th (pre-trail) in 2005–06 to 18th that season, and Mantovani followed the team relegated to Serie B.At Serie B, Mantovani became an absolute starter, started 36 out of 42 matches, missed round 16 and round 22 due to suspension, 1 match as substitute and rested on last round (round 42).In June 2008, he signed a new 4-year contract with club.