Provided are a far infrared reflective film including a support, and a fibrous silver particles-containing layer provided on the support, in which the fibrous silver particles-containing layer includes fibrous silver particles, and a sol-gel hardened material obtained by hydrolysis and polycondensation of a metal coupling agent including a functional group capable of interacting with the fibrous silver particles, and an alkoxide compound, which has excellent heat insulating properties, film hardness, and surface properties; a dispersion for forming a far infrared reflective film; a manufacturing method of a far infrared reflective film; a far infrared reflective glass; and a window.