  Primary goal of the WITCH experiment is to test the Standard Model for a
possible ad-mixture of a scalar or tensor type interaction in beta-decay. This
information will be inferred from the shape of the recoil energy spectrum. The
experimental set-up was completed and is under intensive commissioning at
ISOLDE (CERN). It combines a Penning trap to store the ions and a retardation
spectrometer to probe the recoil ion energy. A brief overview of the WITCH
set-up and the results of commissioning tests performed until now are
presented. Finally, perspectives of the physics program are reviewed.
