  The conductance of a waveguide containing finite number of periodically
placed identical point-like impurities is investigated. It has been calculated
as a function of both the impurity strength and the number of impurities using
the Landauer-B\"uttiker formula. In the case of few impurities the conductance
is proportional to the number of the open channels $N$ of the empty waveguide
and shows a regular staircase like behavior with step heights $\approx 2e^2/h$.
For large number of impurities the influence of the band structure of the
infinite periodic chain can be observed and the conductance is approximately
the number of energy bands (smaller than $N$) times the universal constant
$2e^2/h$. This lower value is reached exponentially with increasing number of
impurities. As the strength of the impurity is increased the system passes from
integrable to quantum-chaotic. The conductance, in units of $2e^2/h$, changes
from $N$ corresponding to the empty waveguide to $\sim N/2 $ corresponding to
chaotic or disordered system. It turnes out, that the conductance can be
expressed as $(1-c/2)N$ where the parameter $0<c<1$ measures the chaoticity of
the system.
