  A large volume time projection chamber (TPC) has been proposed as main
tracking device for a detector at a future linear e+e- collider. Gas electron
multipliers (GEMs) are studied as potential replacement of the conventional
wire based gas amplification system of TPCs. This talk presents recent results
from R&D activities with a small GEM-TPC prototype. The spatial resolution was
measured for different magnetic fields up to 4 T.
