Abstract: A sensor element 101 includes an element main body 101a that includes oxygen ion-conductive solid electrolyte layers (1 to 6), and a porous protective layer 90 that covers at least part of the element main body 101a. The porous protective layer 90 includes a porous inner protective layer 92 and a porous outer protective layer 91 disposed on the outer side of the inner protective layer 92 and having a smaller average pore diameter than the inner protective layer 92.

Abstract: A sensor element 101 includes an element main body 101a that includes oxygen ion-conductive solid electrolyte layers (1 to 6), and a porous protective layer 90 that covers at least part of the element main body 101a. The porous protective layer 90 includes a porous inner protective layer 92 and a porous outer protective layer 91 disposed on the outer side of the inner protective layer 92 and having a smaller average pore diameter than the inner protective layer 92.

Abstract: A method of the present invention is a method for producing a film laminated structure, including the steps of: (a) preparing a ceramic substrate; (b) charging a mold with a slurry that contains a raw material powder, a gelling agent containing at least two polymerizable organic compounds, and an organic solvent serving as a dispersion medium, and molding and hardening the slurry through a polymerization reaction of the gelling agent to form a green body having a recessed portion or through-hole; (c) inserting the ceramic substrate into the recessed portion or through-hole of the green body and then drying the ceramic substrate and the green body to form a green structure; and (d) firing the green structure to form a film laminated structure, the film laminated structure including a film formed from the green body by firing.

Abstract: A method of the present invention is a method for producing a film laminated structure, including the steps of: (a) preparing a substrate; (b) achieving a state that a mold is charged with a slurry that contains a raw material powder, a gelling agent containing at least two polymerizable organic compounds, and an organic solvent serving as a dispersion medium, and that the substrate is placed at a predetermined position in the mold; (c) molding and hardening the slurry through a polymerization reaction of the gelling agent to combine the substrate and a green film to form a green structure; and (d) firing the green structure to form a film laminated structure, the film laminated structure including a porous film formed from the green film by firing.