  The last ten years a number of observational advances have substantially
increased our knowledge of shock phenomena in supernova remnants. This progress
has mainly been made possible by the recent improvements in X-ray and Gamma-ray
instrumentation. It has become clear that some shell-type supernova remnants,
e.g. SN 1006, have X-ray emission dominated by synchrotron radiation, proving
that electrons are accelerated up to 100 TeV. This is still an order of
magnitude below 3E15 eV, at which energy the ion cosmic ray spectrum at earth
shows a spectral break. So one of the major goals is to prove that supernova
remnants are capable of accelerating ions at least up that energy.
  Here I review the evidence that ions and electrons are accelerated up to
energies ~100 TeV in supernova remnants, and, in addition, the recent progress
that has been made in understanding the physics of collisionless shock fronts
and the magnetic fields inside supernova remnants.
