An optical multilayer film comprising a hard coat layer and a low refractive index layer comprising aerogel, which layers are laminated, in this order, directly or with another intervening layer on one surface of a base film comprising a transparent resin, wherein the refractive index n.sub.H of the hard coat layer and the refractive index n.sub.L of the low refractive index layer satisfy the following three formulae [1], [2] and [3], 1.25.ltoreq.n.sub.L.ltoreq.1.37 Formula [1] n.sub.H.gtoreq.1.53 Formula [2] (n.sub.H).sup.1/2-0.2