The fail safety filter is an assistant filter element to be mounted in order to intercept the particles leaked when the main filter elements are broken. So it should have two contrary functions of being plugged easily to meet the purpose of dust sealing and a high permeability to save the space. The permeability of the metal filter elements were effectively controlled by the following factor: powder size(53-840 ${mu}m$) and applied pressure(1000-2000 $kgf/cm^2$), and then the compact were sintered for 1 hour at $1200^{circ}C$ in vacuum sintering furnace. The sintered metal filters was evaluated for the function of the fail safety filter in an experimental unit. The maximum allowable particle size was 420-840 ${mu}m$, when a CIP pressure of 1500 $kgf/cm^2$ was applied reveals a permeability of about $1.2{ imes}10^{10}m^2$ and pore size of about 60 ${mu}m$. The metal filter produced with stainless steel powder of 480-840 ${mu}m$ size, which presented excellent permeability than commercial ceramic filter element and plugged with in 3 minutes with the leak of the maximum particle size less than 3 ${mu}m$.