[en] We have developed a new instrument which performs simultaneously energy and spin-polarization analysis of an electron beam, to be used in spin resolved electron spectroscopies from magnetic surfaces and thin films. The device consists of a novel polarization detector with high efficiency and analyzing power coupled to a large commercial hemispherical energy analyzer (HEA). The spin polarimeter is based on the spin dependence of the low energy (4-6 eV kinetic energy) reflectivity from a magnetic target, namely a Fe(0 0 1)-p(1x1)O surface. We describe reliable target preparation procedures and the design of the electron-optical system transferring the electrons from the HEA exit slit to the polarimeter target