According to police, the dead teenagers include five young men and a young woman and found by the owner of the shed, whose son and daughter were among the victims.
Police in Unterfranken said in a statement, the father made the grim discovery on Sunday morning after wondering why his children hadn't come home from their party the night before.
The victims were all aged 18 or 19.
The incident happened in the town of Arnstein in the southern state of Bavaria.
The police said, "It remains unclear what led to the death of the six people, but police said there were no indications of any violent crime."
The possibility that the six died of carbon monoxide poisoning is among the lines of inquiry, as there was a wood-burning stove in the shed.
Local police spokesman Bjorn Schmitt told the media that the six youths had turned the stove on for heat, so it is a possibility, but there are others.
He further said that upcoming autopsies should provide more information on the cause of death.