The small town is close to the German border and Saarbrücken, the capital of the state of Saarland.
A police source told AFP news agency that the woman, also German, was found naked with her head shaved in a bedroom that was closed off with metal wire.
The police source said the 53-year-old woman had managed to call police in Germany over the weekend, who in turn alerted their French colleagues. The woman said she had been held and abused by her husband since 2011.
French broadcaster BFMTV said that the 55-year-old man is accused of kidnapping, aggravated rape, and acts of torture and barbarism. He is held in the eastern French city of Metz.
The investigations are ongoing. French-Monegasque station RMC said police found a diary-like notebook in the apartment, which the man is believed to have used to record his actions and the times he gave his wife food.