Nuclear power has not been as popular in the Nordic country since 1997, reported the regional daily Aamulehti, which commissioned the poll.
In 2000, support for nuclear energy stood at around 40 percent, but it has since increased steadily to 50 percent this June, it said.
According to the survey, conducted among 1,000 Finns earlier this month, nearly 44 percent of those polled were against increased use of nuclear power, while under seven percent abstained from answering.
The research, carried out by pollster Taloustutkimus, has an error margin of 2.5 percent, according to the daily.
Currently, 28 percent of Finland's power is supplied by its four nuclear reactors, a figure which is expected to increase to 35 percent at the end of this decade when the new reactor is finished.