The flight from Paris Charles de Gaulle to Cairo normally takes just over four hours and the EgyptAir flight - which had 66 people on board - was due to arrive at 3:05am local time.
EgyptAir said in a statement that the flight was carrying 15 French passengers and 30 Egyptians. There was also a Brit, a Canadian, an Algerian, a Belgian, a Chadian, two Iraqis, a Kuwaiti, a Portuguese, a Saudi and a Sudanese on board the flight.
EgyptAir also confirmed that there were two babies and one child among the passengers.
No information has yet been released from the airline about the identities of the passengers, but Amiens-based France Bleu Picardie reported that Procter & Gamble's manager in Amiens, Ahmed Helal, was on board and that employees of the company had been informed.
The were ten staff members on board, made up of two cockpit crew, five cabin crew and three security personnel.
Egyptian newspaper Ahram Online named the pilot of the flight as Mohamed Shokeir, who has over 6,000 flight hours, and said that his copilot had over 2,000 flight hours.
The airline said in a statement that it has contacted the families of those who were on the flight, many of whom are at the Cairo airport. Egypt Air is hosting the families near the airport and has provided doctors and translators.
In Paris, a crisis centre has also been set up for relatives at Charles de Gaulle airport where the flight originated. Two relatives of passengers had arrived there this morning and were being taken care of by psychologists, according to reports in Le Figaro.
In France, a help hotline has been set up: 01 43 17 55 95
Foreign Minister Jean-Marc Ayrault said his team was working with Egypt embassy officials to gather information on the plane's disappearance. "I share the anguish felt by the passengers' families," he said.
A tweet on the airline's official account said flight MS804 left Paris at 11:09 pm local time (2109 GMT), "heading to Cairo (and) has disappeared from radar".
Further tweets in Arabic said contact was lost at 2:45 am Cairo time (0045 GMT), when the plane was just inside Egyptian airspace and at an altitude of 37,000 feet (11,000 metres).