A civic group who filed a criminal complaint against the three former executives of Tokyo Electric Power Company has demanded that prosecution should appeal against the non-guilty ruling.
The leader of the group, Ruiko Muto, has told a news conference that the ruling is totally unacceptable.
Muto said she believes the court's rejection of a motion, demanding that it conduct field inspections of the nuclear disaster area in Fukushima, was unjust.
The news conference was also attended by Yuichi Kaido, one of the lawyers representing the relatives of people whose deaths are blamed on the nuclear accident.
Kaido said the ruling was far worse than he had ever expected. He said the ruling will leave a large blemish in the history of Japan's justice system, and it should be overturned.
Kaido said he urges the court-appointed lawyers who served as prosecutors in the case to appeal against the ruling. He said he sincerely hopes that justice will be served at the appeal court.