An additional 50 others were wounded in the blast at St. George (Mar Girgis) Coptic church in Tanta, it said.
The explosive device was planted under a seat in the church, where it detonated in the main prayer hall.
"Terrorism hits Egypt again, this time on Palm Sunday. Another obnoxious but failed attempt against all Egyptians," the Foreign Affairs ministry tweeted.
Palm Sunday is the Sunday before Easter, and marks the start of Holy Week for Christians. Social media video showed crowds gathered outside the church shortly after the attack.