It is an object of the present invention to provide a porous body containing an oxide semiconductor in which more efficient photocatalytic reactions and photoelectrode reactions occur. The present invention relates to a porous body having a network structure skeleton wherein 1) the aforementioned skeleton is composed of an inner part and a surface part, 2) the aforementioned inner part is substantially made of carbon material, and 3) all or part of the aforementioned surface part is an oxide semiconductor, and to a manufacturing method therefor.