Senior staff at his primary school, on a council estate in East Anglia, installed the miniature camera last term after hearing about the allegations he faced at the secondary where he previously taught.
Other teachers have used the classroom to hold meetings with parents and say the CCTV has deterred violent behaviour.
The special educational needs teacher, who does not wish to be named, said:
"It is horrible having to take such precautions, but I am not taking any chances."
The pound;100 camera records sound as well as wide-angle images of the small classroom, which are transmitted to a video recorder and television in the staffroom.
There have been no complaints from parents or pupils who have been told of the CCTV.
The move comes as growing numbers of nursery schools follow the example of Gorringe Park primary in Merton, London, by installing webcameras so parents can keep an eye on their children. Teaching unions this week said they would support schools installing cameras, but David Hart, general secretary of the National Association of Head Teachers, said: "This really is a sign of the times."
Over the past decade, nearly 1,000 members of the National Association of Schoolmasters Union of Women Teachers faced police investigation into physical or sexual abuse, but just 52 were convicted, according to the union.
A Department for Education and Skills spokeswoman was unaware of any reason why schools could not install cameras. It was up to headteachers to arrange supervision and good behaviour in their classrooms.
However, civil liberties group Liberty warned that constant monitoring could cause pupils psychological problems. Mark Littlewood, campaign director, said: "This seems like overkill. We are soon going to get parents saying, 'You say Jimmy's been misbehaving - well, show me the tape'."