The emergency services were alerted around 2.20am on Saturday when an automatic alarm was raised at the school in the Hisingen area of the city.
Around 50 firefighters from three stations were called to the scene but were unable to counter the flames in time to save the building.
”In principle the whole school has been destroyed,” Kent Andersson from the city’s fire department told the Göteborgs-Posten newspaper.
Thick, black smoke continued to be visable from the building on Saturday morning and local residents were advised to stay indoors and keep windows and doors closed.
The fire was eventually exhausted around lunchtime on Saturday.
The local fire department believe the fire was deliberately started in car, which was parked close to the entrance of the school.
No one is reported to have been injured in the fire and police have begun their inquiries into the incident. A forensic investigation is also due to take place.
The fire affects around 500 high school students who attended Torslanda school.