There is provided an inorganic particle composite body comprising a layer of a substrate formed of a plastically deformable solid material and an inorganic particle layer that is composed of inorganic particles that do not plastically deform under a condition under which the solid material plastically deforms, that contains gaps defined by the inorganic particles, and that adjoins the layer of the substrate, wherein part of the solid material is in at least part of the gaps in the inorganic particle layer. This inorganic particle composite body is produced by a method including a preparation step of preparing an inorganic particle structural body comprising a layer of a substrate formed of a plastically deformable solid material and an inorganic particle layer that is composed of inorganic particles that do not plastically deform under a condition under which the solid material plastically deforms, that contains gaps defined by the inorganic particles, and that adjoins the layer of the substrate; and a filling step of plastically deforming at least part of the solid material contained in the inorganic particle structural body, thereby filling at least part of the gaps in the inorganic particle layer with part of the plastically deformed solid material.