The victim was targeted in the north of the region on Saturday by three masked gunmen, according to staff quoted by Associated Press.
The death of the 35-year-old, who has been named as Bassem Attallah, marks the latest in a spate of attacks affecting believers in Egypt.
Associated Press quoted security officials who spoke on condition of anonymity because "they were not authorised" to communicate with journalists.
More than 100 believers have died in a series of bombings and shootings - many perpetrated by Islamic State - since December 2016.
No one has claimed responsibility for Saturday's attack in northern Sinai, which displayed the hallmarks of IS extremists - who have been particularly active in Sinai in recent months.
In Cairo, nine people were killed during a shooting by two gunmen at Marmina Church in the city's Helwan district on Friday 29th December 2017 (pictured above).
Coptic Christians are the biggest religious minority in Sinai, and comprise ten per cent of Egypt's total 93 million population.
Believers in Egypt have long complained of the threat of sectarian violence and institutional discrimination and there has been repeated pledges by President Abdel Fattah el-Sisi to protect Christians.
Top image: Library image of Egyptian military police