A light diffuser includes: a thermoplastic resin base which has a thermal expansion coefficient of at least 4×10−5/K and at most 8×10−5/K; and a light diffusion layer which is disposed on a surface of the thermoplastic resin base and includes an acrylic resin film and an acrylic resin particle, the acrylic resin film including one or more acrylic resins having a glass transition temperature of at least 30° C. and at most 50° C., the acrylic resin particle being included in the acrylic resin film and having an average particle size of at least 1 μm and at most 15 μm.