  Conductance quantization was measured in submicron constrictions of PbTe,
patterned into narrow,12 nm wide quantum wells deposited between
Pb$_{0.92}$Eu$_{0.08}$Te barriers. Because the quantum confinement imposed by
the barriers is much stronger than the lateral one, the one-dimensional
electron energy level structure is very similar to that usually met in
constrictions of AlGaAs/GaAs heterostructures. However, in contrast to any
other system studied so far, we observe precise conductance quantization in
$2e^2/h$ units, {\it despite of significant amount of charged defects in the
vicinity of the constriction}. We show that such extraordinary results is a
consequence of the paraelectric properties of PbTe, namely, the suppression of
long-range tails of the Coulomb potentials due to the huge dielectric constant.
