The 19-year-old man was in detention for violent criminal offences.
“He tore down parts of his ceiling and climbed up to the top floor, using a ventilation shaft to exit the building,” said Roger Götheden of Västmanland police to news agency TT
Police dog patrols were searching for the man on Sunday morning in the immediate vicinity of the centre. He is reported to be from the Stockholm area.
Sundbo detention centre houses males between the ages of 15 and 21. The centre caters to criminally active youths with serious psycho-social problems and histories of substance abuse.