The 17-year-old pupil at a vocational lycee in Longwy, north-east France, was regularly tortured by three fellow pupils.
His ordeal began last October, when his attackers used equipment in a school workshop to beat him. They burnt his arms and neck with red-hot copper piping, hammered his fingers or squeezed them in pincers, and crushed his hands in a vice.
The victim was too frightened to complain, and the bullying was uncovered only when a younger pupil told the deputy head.
The discovery of the torture and a series of teacher strikes over pupils' violence prompted education minister Claude Allegre to annouce new anti-violence measures yesterday.
The minister and his deputy Segolene Royal expressed their "indignation at the acts of barbarity" and called for "exemplary judicial treatment for these extremely serious deeds". They announced an urgent inquiry into the affair and the "law of silence" that had prevailed.
Meanwhile teachers and security guards walked out last week after a pupil threw an acid-filled Molotov cocktail into the lobby of a school in the deprived Paris suburb of Seine-Saint-Denis. This was the fifth violent incident in the school since term began.
The government said serious incidents have occurred in about 40 schools nationwide and promised measures including extra funds and a policy of zero tolerance of violent behaviour.