Derby City Council has been fined £50,000 with costs of £20,000 after admitting asbestos safety breaches.
The school was closed for several weeks
The case follows an incident when a Mickleover school closed for several weeks after asbestos was disturbed during window replacement work.
Peter Westran - who owns and runs Horizon Windows and Glass, which carried out the initial window repairs - was fined £5,000.
His company was fined a further £10,000 at Nottingham Crown Court.
Potentially deadly brown asbestos was disturbed when windows were being replaced during February and March 2004 at Silverhill Primary School at Mickleover, Derby.
Both staff and pupils were present during the work, which lasted three weeks.
The work was stopped once the problem was identified and the school was closed for several weeks while decontamination work was carried out.
The final bill for the clear-up and replacement of equipment was £640,000.
The prosecution was brought by the Health and Safety Executive (HSE).