| abstract |
Provided is a porous material excellent in heat insulating property, mechanical property, and surface properties (such as adhesiveness and abrasion property). The porous material is a polymer porous film of a single layer, including a first porosity size changing portion ( 613 ) formed of independent porosities each showing a gradual increase in porosity size across a region accounting for 10% or more of a film thickness from a first surface side ( 611 ) toward a second surface side ( 612 ). |