An Egyptian solider was shot dead by unidentified gunmen in central Sinai late on Saturday, state news agency MENA reported.
The shooting took place amid a weeks-long military campaign to rid the lawless peninsula of Islamist insurgents .
The soldier was shot at a security checkpoint in the town of Al-Qusayma, the second soldier to be killed by Islamist militants in Sinai that day.
Another was shot dead on Saturday morning in the northern Sinai town of Sheikh Zuwayid.
Egyptian troops and military equipment have poured into the Sinai Peninsula to combat a militant insurgency  which has surged since the overthrow of Islamist president Mohamed Morsi on 3 July.
Militant activity in Sinai, adjoining Israel and the Palestinian Gaza Strip, has killed more than a hundred military personnel and policemen in almost daily attacks over the past two months.
A Sinai-based militant group, Ansar Beit Al-Maqdis, claimed responsibility for a failed assassination attempt against Egypt's interior minister on 5 September.
The military says it has killed dozens of Islamist militants , and captured hundreds of others during its assault targetting weapons depots and militant hideouts in the region.
Hundreds of Islamists have been killed and upwards of 2,000 arrested in a nationwide crackdown since Morsi's ouster.