The results of TPC tests in an accelerator beam are described. This chamber with a 800 x 350 x 60 mm 3 sensitive volume is a module of a large TPC with dimensions 800 x 350 x 1600 mm 3. The coordinate along the signal wires is determined by means of electromagnetic delay lines. The chamber operates with a track efficiency of > 90% and a spatial resolution of 0.2∼0.5 mm for the electron drift and 1–1.5 mm for the delay lines. The TPC module operates with high efficiency in the magnetic field with B = 1.5 T as well. The chamber was investigated using beams with intensities up to 10 6 particles/s. An electric gate, designed for the trigger mode of the chamber operation, was tested in the beam both with and without the magnetic field.