An apparatus for manufacturing a composite structure body is provided which forms structure body having the constitution in which the crystals of more than one type of brittle material are dispersed and having novel properties without involving a heating/sintering process. The apparatus includes an aerosol generator configured to generate an aerosol. The aerosol is generated through dispersing fine particles of more than one type of brittle material, or dispersing composite fine particles, in a gas. The apparatus also includes a nozzle configured to spray the aerosol, a classifier configured to classify the brittle material fine particles in the aerosol, and a disintegrating machine for disintegrating agglomerations of the brittle material fine particles in the aerosol. The composite structure body is manufactured in reduced pressure conditions by bombarding a substrate with the aerosol at a high velocity, whereby at least one of crystals and microstructures of said brittle materials are dispersed.