Hubert Ballaman was seized by armed men in Abeche, a key garrison town for the army and police and where the UN peacekeeping force is also based.
Chad’s prime minister said security forces had intercepted the abductors near the border with Sudan, AFP news agency reports.
Mr Ballaman is reported to be in good health.
"At the moment, the freed hostage and his abductors are in the hands of the forces of defence and security in the east of the country," said Prime Minister Emmanuel Nadingar.
Last month, the Chad government asked the UN Security Council to withdraw the peacekeepers by the end of the year.
The 4,375-strong Minurcat force was deployed to protect hundreds of thousands of displaced Chadians and refugees from the Sudanese province of Darfur.
Source: BBC