  The magnetic susceptibility and magnetization of high quality single crystal
beta-TeVO4 are reported. We show that this compound, made of weakly coupled
infinite chains of VO5 pyramids sharing corners, behaves as a S = 1/2
one-dimensional Heisenberg antiferromagnet. From magnetic experiments we deduce
the intrachain antiferromagnetic coupling constant J/kB = 21.4 $\pm$ 0.2 K.
Below 5 K a series of three phase transitions at 2.26, 3.28 and 4.65 K is
observed.
