Abstract: A method for producing hollow silica particles having an average particle diameter of 0.5 ?m or more and 3.0 ?m or less and a total content of alkali metals and alkaline earth metals of 50 mass ppm or less with respect to a content of the silica in the particles, wherein the hollow silica particles have a relative permittivity of 2.5 or less and a dielectric dissipation factor of 0.0050 or less at a measurement frequency of 5.8 GHZ, and the method includes the following steps. Step A: a step of making an aqueous emulsion of a hydrophobic liquid using a cationic surfactant A; Step B: a step of adding, to the aqueous emulsion obtained in Step A, a silanol precursor, an alkaline substance, and a cationic surfactant B, and generating a hollow silica particle precursor; Step C: a step of heat-treating the hollow silica particle precursor obtained in Step B at a temperature higher than 1000° C. and 1200° C. or lower for one hour or more.

Abstract: [Problems] To provide a method for industrially producing carbon-containing silicon carbide ceramics having excellent structural and other various physical properties after sintering, especially density and strength. [Solving Means] A method for producing carbon-containing silicon carbide ceramics including the step of burning a mixture X of raw materials containing silicon carbide, a carbon raw material, and a sintering aid, wherein the particles constituting the mixture X have an average particle size of from 0.05 to 3 ?m.