"We can say today that the Ebola epidemic has been completely subdued - having observed a period twice the length of the disease's incubation period without any new infections," Health Minister Makwenge Kaput said.
The incubation period for Ebola is about 15 days, and outbreaks are usually considered contained when twice the incubation period has passed.
The Ebola outbreak was first discovered in the area of Kampungu in August. Public health experts flew in from around the world to help contain the virus.
Congo's last major Ebola outbreak in 1995 killed 245 people in Kikwit, about 185 miles (300 kilometers) from the site of this year's outbreak.
It was initially difficult to assess the size of the outbreak because many of the sick had diseases with similar symptoms such as typhoid, malaria and shigella, said Dr. Vital Mondonge, a health ministry official.
Twenty-one cases were confirmed in all, six of which ended in death, Kaput said. A spokesman for the World Health Organization had previously said that 21 people had died of Ebola in the outbreak. Kaput said this number was incorrect, the result of a misreading of the figures.
The Zaire subtype of Ebola detected in the Congo can kill up to 90 percent of people infected. The virus attacks the body's internal organs, and can cause bleeding from the ears, eyes and elsewhere.
Doctors said in early October that they believed they had contained the Ebola outbreak, but health officials needed to wait out the incubation period to be sure.
Ebola is transmitted by close contact with infected animals or humans. Experts say the current outbreak may have started when villagers in the area ate an infected animal. It was then probably spread at several funerals, where people typically touch the body during the ceremony.