A Ag aerogel-like film (referred to as aerogel hereafter), used as a thermal interface material with enhanced performance and thermal stability, is reported. An aerogel/ foil/aerogel "monocomposite" is created by rapidly forming and depositing Ag nanoparticles on both faces of a Ag foil by the gas-evaporation and particle-deposition method in a few minutes. The monocomposite, having an aerogel of a low packing ratio (<10%) with a clean surface, exhibits low thermal resistance (18 mm 2 K W −1 ) when sandwiched with Cu rods. The monocomposite exhibits excellent thermal stability and significantly reduced thermal resistance (3.0 mm 2 K W −1 ) at 246 °C, keeping its low thermal resistance (2.8 mm 2 K W −1 ) after the temperature is decreased to 51 °C; further, the resistance reduces to 2.1 mm 2 K W −1 after 10 cycles of heating and cooling (100−200 °C). The Ag monocomposite, having high performance comparable to that of the benchmark In sheet and excellent thermal stability at a temperature higher than the melting point of In, will enable high-power and high-temperature operation of computing and power devices.