Abstract: The present disclosure provides a separator for an electric storage device, which separator is capable of reducing clogging and has an excellent thermal stability, and an electric storage device using the same. The above-described separator for an electric storage device includes a microporous layer (A) and a microporous layer (B) that contain 70 wt % or more of polypropylene, and the area average major pore diameter in an ND-MD cross section of the microporous layer (B) is not more than 0.95 times the area average major pore diameter in an ND-MD cross section of the microporous layer (A). Alternatively, the separator for an electric storage device contains 70% by weight or more of a polyolefin, and the area average major pore diameter of a first porous surface (X) of the separator is not less than 1.05 times and not more than 10 times the area average major pore diameter of a second porous surface (Y) on the side opposite thereto.

Abstract: A vapor chamber in which an enclosed space is formed, and a working fluid is sealed in this space, the enclosed space including: a plurality of condensate flow paths through which a fluid that is the working fluid in a condensing state flows; and vapor flow paths through which a vapor that is the working fluid in a vaporizing state flows, wherein each of projecting parts with which each of the vapor flow paths is provided has a projecting amount varying in an extending direction of the vapor flow paths; a pitch for opening parts that allow the vapor flow paths and the condensate flow paths to communicate varies in the extending direction of the vapor flow paths; or wall parts that separate the flow paths each have a given relationship with a transverse cross section of a given flow path.