Abstract: A process for producing a silicate foam having a low density, which comprises the following steps: (a) partial hydrolysis of an aqueous dispersion of SiO2 particles which have an average particle diameter in the range from 1 to 100 nm by means of a strong base, (b) addition of a surfactant and a blowing agent and dispersion of the blowing agent at temperatures below 50° C., (c) foaming of the mixture by heating to a temperature in the range from 35 to 100° C. or by depressurization, (d) stabilization of the foam obtained in step c) by means of a hardener, (e) sintering of the foam at a temperature above 500° C.