An efficient method for the preparation of a foamed and cured silicone rubber body having a uniform fine-cellular structure, in which a foamable silicone rubber composition is prepared by uniformly compounding a diorganopolysiloxane, finely divided silica filler, titanium dioxide powder, blowing agent and curing agent, each in a specified weight proportion, and irradiating the thus prepared composition with microwaves having a frequency of 900 to 5000 MHz which, by virtue of the titanium dioxide powder having a high dielectric constant, are efficiently absorbed and converted to heat, whereby the composition is evenly heated throughout the body to cause uniform foaming and curing.