Judge Ahmed Aboul Fotouh was one of three judges that sentenced the former president to 20 years in jail.
An Egyptian judge who tried former president Mohamed Mursi in 2015 survived an assassination attempt on Friday when a parked car exploded as his vehicle drove by, the Interior Ministry said.
The target was Judge Ahmed Aboul Fotouh, who presides over a felony court in a district of Cairo. The blast caused no injuries, the ministry said in a statement.
Judges, policemen and other senior officials have increasingly been targeted by radical Islamists angered by the hefty prison sentences imposed on members of the now-outlawed Muslim Brotherhood.
A newly-emerged militant group, the Hasam Movement, claimed responsibility for Friday's bombing, which occurred in the eastern Cairo neighbourhood of Nasr City.
"The Hasam Movement's central bombing squad targeted the regime's dog and one of hell's judges Ahmed Aboul Fotouh using a car bomb near his house," the group said in a statement.
"To every unjust judge you still have a chance to think it through and leave this dirty swamp that is unfairly referred to as the judiciary."
Aboul Fotouh was one of three judges on a panel that in April 2015 sentenced Mursi, also a senior official in the Brotherhood, to 20 years in jail after finding him guilty of inciting violence that led to the death of 10 people in clashes with security forces in December 2012.
The Brotherhood, which says it is a peaceful organisation, won Egypt's first free elections after the 2011 uprising that ended Hosni Mubarak's 30-year rule.
But Mursi, its presidential candidate, was himself deposed after mass protests against his rule and replaced in 2013 by the then-head of the armed forces who is now the president, Abdel Fattah al-Sisi.
Sisi has since overseen a crackdown on the opposition in which hundreds of Brotherhood supporters have been killed and thousands, including Mursi, jailed or sentenced to death.
Hasam - an acronym in Arabic for the Forearms of Egypt Movement that doubles as the word for decisiveness - has claimed seven attacks since July, including the one on Friday.
It says it is responsible for an attempt to assassinate of a senior prosecutor with a car bomb and an attempt to gun down Egypt's former top Muslim cleric. The group also killed a senior police chief earlier this year.
The group's statements mix Islamist rhetoric with anti-government slogans, setting it apart from jihadist groups such as Islamic State, which is leading an Islamist insurgency in North Sinai and has killed hundreds of soldiers and police.
The Interior Ministry said on Friday it had arrested members of Hasam and another new militant group, along with weapons, explosives and evidence that the organisations had been set up by the Muslim Brotherhood. There was no immediate comment from the Brotherhood.