An aluminum vacuum chamber 3 m long and 21.5 mm high was fabricated, tested and installed in the wiggler section of the Taiwan Light Source at the Synchrotron Radiation Research Center. The chamber was made by the extrusion method and machined to a flatness of < +/- 0.1 mm/(3) m. The inner aperture included an elliptical channel (17 mm x 80 mm) for electron beam and a pumping channel for a nonevaporable getter (NEG) strip. Two heat-treated Be-Cu springs were used to absorb the thermal expansion of the NEG strip during activation. After installation of the wiggler chamber in the storage ring, a pressure of 0.45 nTorr was reached after an in situ bakeout with NEG activated, The high temperature properties of the Be-Cu spring and the vacuum performance of the complete chamber have been tested. No obvious influence, due to the narrow beam aperture or limited gas conductance to the beam life time was found.