A width-direction multilayer laminated film having a large area and uniform optical properties is provided. A light guide, a light diffusion film, a light collecting film, a viewing angle control film, and an optical waveguide film, which are low cost and have excellent optical properties, as well as an illuminating device, a communication device, and a display using these films. The laminated film may include at least a structure in which a layer made of resin A (layer A) and a layer made of resin B (layer B) are alternately laminated in the width direction, wherein the width of the film is 400 mm or more and the number of layer Bs, each having a cross-sectional width from 0.1 μm to 10,000 μm, is 10 or larger.