A large area streamer tube detector, located within the KASCADE experiment, has been built with the aim to identify muons and their directions from extensive air showers by track measurements under more than 18 r.l. shielding. 1000 streamer tube chambers of 4 m length have been produced and tested. The detector concept is presented. The influence of the design and operational factors on the detector performance are shown. Various approaches to determine the angular resolution of the muon tracking detector are discussed. r