The sequential quadruple Auger decay of the Xe $4s$ core-hole state has been investigated by multielectron-ion coincidence spectroscopy using a magnetic bottle electron spectrometer. The high collection efficiency for electrons and ions enables sixfold coincidence measurement of all the emitted electrons and the product ${\mathrm{Xe}}^{5+}$ ion. While the Auger electrons emitted in the different Auger steps greatly overlap each other in energy, step-by-step analysis of the energy correlation among Auger electrons in coincidence discloses two important quadruple Auger decay pathways.