The Islamic State group affiliate in Egypt has claimed it downed the aircraft, but has not said how it might have done so.
Cairo and Moscow, however, have denied any possible terrorism link in the incident, one of the deadliest Airbus crashes in the past decade.
This evening, the prime minister's office said: 'The black box was recovered from the tail of the plane and has been sent to be analysed by experts.'
It added that more than 45 ambulances have been dispatched to the crash site, with rescuers having recovered 129 victims' bodies so far.
The jet, which was leased by a Russian airline and carrying package holiday passengers back to St Peterburg in northern Russia, plummeted to the ground less than 25 minutes after it took off from the Red Sea resort of Sharm el-Sheik.
It crashed in the Hassana area, south of Arish, officials said.
Security forces discovered the plane wreckage in a remote mountainous area in a region containing many ISIS-affiliated terrorists.
Ismail told reporters experts will 'start examining the information in the plane's black box, and based on this we will study the causes of the crash'.
He also expressed scepticism about ISIS's claim that it carried out the attack in response to Russian strikes in Syria.
The ISIS statement read: 'The soldiers of the caliphate succeeded in bringing down a Russian plane in Sinai.'
But Islami claimed: 'Experts have affirmed that technically planes at this altitude cannot be shot down, and the black box will be the one that will reveal the reasons for the crash,' according to state news agency MENA.
Russian transport minister Maksim Sokolov also dismissed the ISIS claims. He said: 'This information cannot be considered accurate.
We are in close contact with our Egyptian colleagues and aviation authorities in the country. At present, they have no information that would confirm such insinuations.'
While the use of a surface-to-air missile has been dismissed as a potential cause of the crash by officials, an on-board bomb could be a possibility.