The man, from the Zurich area, was arrested yesterday while seeking to board a plane to Istanbul, Turkey.
The unidentified man was accused of having links to a group banned in Switzerland and supporting a criminal organisation.
The arrest demonstrates "the systematic legal pursuit of all people in Switzerland who are trying to take part in jihadist terrorism," the prosecutors said.
Last year, two people were sentenced to prison for backing a criminal organisation and public appeals to violence -- a reference to Internet propaganda.
The rising numbers of Europeans going to fight in Iraq and Syria have worried governments who fear that battle-hardened veterans could return and unleash terror attacks and violence.