Federal police said the man's motive was unclear but there was no indication the incident was terror-related.
Airport traffic was suspended at Hannover airport on Saturday after a vehicle crashed through a barrier onto the runway, police said.
Officers managed to "overpower" the man, who drove a Polish-registered auto, and arrest him.
Police later added: "Police checks of the vehicle have been completed, no unsafe objects were found".
A auto with Polish license plates entered through a passageway onto the tarmac around 15:30 local time, prompting a major federal police response and deployment of explosive teams.
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Airport staff announced flights had resumed at 8.05pm local time (7.05pm GMT).
"The security areas are now vacated, now there is no clearance", police said, immediately after the incident.
All flights have been suspended after the incident happened at 3.40 local time on Saturday.
They couldn't give further information about where he came from because he was not carrying an identity card.
The Hannover airport isn't one of Germany's major hubs.