<p>Provided is a separator made of a laminated porous film in which a heat-resistant layer that comprises a heat-resistant resin and a shut-down layer that comprises a thermoplastic resin are laminated, wherein the heat-resistant layer further comprises two or more fillers, and the value of D 2 /D 1 is 0.15 or less where among values each obtained by measuring the average particle diameter of particles that constitute one of the two or more fillers, the largest value is let be D 1 and the second largest value is let be D 2 .</p>
