He also planned to spread toxic gas through the ventilation systems and had explosive substances in his home.
But Eurovision was cancelled and by then the man had already been arrested by the police, suspected of, among other things, crimes against the country's terrorism laws.
In his home, the police are said to have found a document with detailed plans for how the attack on Eurovision would be carried out.
The man, who was a minor at the time of the incident, now risks twelve years in prison.
He has previously been convicted of burning down a mink farm in Sweden. He is also said to have ties to Nazi white power organizations with a focus on eco-fascism.