Eau Claire Fire and Rescue was called to a building fire early Monday morning.
Battalion Chief Duane Grunst said the fire started at 1:40 a.m. at Presto Absorbent Products on North Hastings Way in Eau Claire.
Fire crews said a diaper machine caught fire inside the plant.
The plant was in operation when the fire started and all personnel were evacuated.
Fire crews said there were no injuries.
They said the fire was extinguished by several fire extinguishers and fire crews left the scene by 4 a.m.
The diaper machine had a value of approximately $1.5 million, but a total damage amount has not yet been reported.