  For experiments of the type A(\vec e,e'\vec p) the 3-spectrometer setup of
the A1 collaboration at MAMI has been supplemented by a focal plane
proton-polarimeter. To this end, a carbon analyzer of variable thickness and
two double-planes of horizontal drift chambers have been added to the standard
detector system of Spectrometer A. Due to the spin precession in the
spectrometer magnets, all three polarization components at the target can be
measured simultaneously. The performance of the polarimeter has been studied
using elastic p(e,e'p) scattering.
