  Performances of the Very Forward Proton Spectrometer (VFPS) of the H1
detector at HERA using data collected during the 2006/2007 running period are
discussed, including the description of acceptance, reconstruction of proton
energy loss and estimation of the amount of the beam-gas background. The first
physics result obtained with the VFPS detector - a preliminary measurement of
the semi-inclusive reduced cross section is presented for the diffractive deep
inelastic scattering process with the leading final state proton measured by
the VFPS. Results of this measurement are found to be in agreement with other
measurements by the H1 Collaboration and with a theoretical prediction based on
a NLO DGLAP QCD fit. They provide a higher precision and therefore allow a
deeper inside to the nature of diffraction.
