One-dimensional scattering by an arbitrary finite periodic potential i
s considered. Closed expressions for reflection and transmission (tunn
eling) amplitudes and probabilities are obtained. Equations determinin
g the positions of transmission resonances are derived. The appearance
of a band structure of the energy eigenspectrum as the number of barr
iers increases is investigated. The application of the results for the
description of the reflection of X-rays incident under an angle sligh
tly above the critical angle for total external reflection on the supe
rlattice structures is discussed.