An army statement said Monday that the man confessed to accepting money in return for spying and that he traveled to Israel three times since 1999.
The army says Lebanese authorities found in his home equipment used for spying and CDs with pictures of security locations.
More than 100 people have been arrested in Lebanon since 2009 on suspicion of spying.
Lebanese officials maintain that Israel regularly recruits spies in Lebanon and has penetrated the country’s telecommunications networks.
The two countries remain in a state of war.