The aircraft, which has an advanced onboard computer, satellite communication and radar systems, was delivered to the Air Force in October and started flight tests.
It will participate in all major military exercises this year, the spokesman added.
The aircraft now has the capability to detect various types of flying targets, including helicopters, cruise missiles and supersonic aircraft, he said.
The Beriev A-50, based on the Ilyushin Il-76 transport, first flew in 1978. It entered service in 1984, with about 40 produced by 1992.
The A-50 can track up to 10 fighter aircraft for either air-to-air interception or air-to-ground attack missions.