After compression of a system formed by a nanoporous media and a non-wetting liquid to the threshold pressure value, the liquid fills the pores of a porous media. In accordance with prevailing concepts, passage of the liquid from the bulk to the dispersed state can be described as a percolation-type transition. This process is typical of infiltration of macroscopic porous bodies with wetting liquids. The threshold type of infiltration was observed for non-wetting liquids and is scientifically detailed in this book.