The present invention provides a nonaqueous electrolyte electricity storage device including a separator that can be produced by a method in which use of a solvent that places a large load on the environment can be avoided and in which control of parameter...

The present invention relates to a porous membrane containing cellulose fibers, wherein the cellulose fibers contain 5% by weight or more of cellulose fibers with a diameter of 1 µm or more, relative to the total weight of the cellulose fibers, the mode d...