Increasing the yield of separating membranes in treating them with gas-discharge plasma ions was investigated. A plasma-chemical method of modifying polymer and metal-ceramic membranes that allows obtaining membranes with adjustable pore size was developed. In treating a metal-ceramic membrane in plasma with organoelemental compound vapors, the pore size in the surface layer decreases to similar to 25 nm. A membrane block for treating gas emissions to remove finely disperse industrial carbon was created based on metal-ceramic and metal membranes undergoing plasma-chemical treatment.