The Duesseldorf regional court on Friday sentenced the German-Tunisian defendant, whose name wasn't released for privacy reasons, to five years in prison.
Judges concluded that the man had sent night vision devices, firearms-cleaning equipment and ambulance vehicles to the militia group Ahrar al-Sham. He is also accused of having provided propaganda support to the Islamic State group.
The defendant's lawyers had sought to have their client acquitted.
German news agency dpa reported that the defendant had described himself as a “cyber jihadist” on social media platforms. Authorities found an IS training video on his laptop showing the killing of people.