The fire broke out on Christian Ridge Road just after 8:30 p.m.
Everyone got out safely, according to fire officials.
Fire officials said the fire started in the back of the building, but they were able to put it out quickly.
They said fire crews had to cut a hole into the roof to vent out smoke.
Multiple departments from neighboring areas responded, including Lamoine, Hancock, Surry, and Dedham.
Ellsworth Fire Chief Richard Tupper said crews had to go up a small stairwell to get to the fire, making things more difficult.
"Very confined access to the second floor was a problem," said Chief Tupper, "and manpower is always an issue at the onset of the incident."
Fire damage to the building was minimal, but Chief Tupper said there is water damage.