The possibility of obtaining a Si-SiO₂ nanocomposite layer by oxidation of porous silicon is demonstrated. The nanocomposite thus prepared consists of silicon oxide with inclusions of crystalline silicon in the form of rounded particles 5 to 30 nm in diameter and a filamentary cellular structure with filaments a few nanometers thick. The I-V characteristics of these structures were measured under different sample excitation conditions (photo- and thermal stimulation). The trap concentration and effective carrier mobility are estimated. Carriers are found to be captured intensely by traps created in the large-area interface in the composite structure.