"Unidentified gunmen opened fire on a Defense Ministry unit while it was conducting a reconnaissance mission in a forested area," a spokesman said.
The incident took place late Sunday in the Shatoi district, about 30 miles to the south of the Chechen capital, Grozny.
The spokesman said the serviceman was in hospital, in a satisfactory condition.
Law-enforcement agencies are carrying out measures to find and apprehend the attackers, he added.
Although the last war in Chechnya officially ended in 2001, periodic bombings and clashes between gunmen and federal troops still disrupt the republic's relative calm, with the violence often spilling over into adjacent regions.
In November, one police officer was killed and four wounded in a road bridge bombing in Grozny, and another officer was killed in a car attack in the republic's Kurchaloi district, southeast of Grozny. A number of servicemen were wounded in an armed clash with militants.
The commander of Russia's Joint Forces in the North Caucasus, Colonel-General Yevgeny Baryayev, earlier said about 700 gunmen continue to operate in Chechnya and neighboring regions.
Following the killing of Chechnya's number one terrorist, Shamil Basayev, Russian authorities announced a partial amnesty July 15 for militants who were not involved in major atrocities.
A law granting amnesty to militants and servicemen guilty of offenses during the North Caucasus antiterrorism campaign came into force in late September.
Officials say more than 300 militants have surrendered since then, mainly in Chechnya.
