A method of producing a microlens array includes a patterning step of forming a first optical resin layer having a first refractive index on a transparent substrate and forming a plurality of microlens planes arrayed in a two-dimensional pattern on the front surface of the first optical resin layer; a planarizing step of forming a planarized second optical resin layer; a joining step of providing a support layer on which a transparent protective film is previously formed; and a removing step of removing the support layer in such a manner that only the protective film remains on the second optical resin layer. The planarizing step is performed by filling irregularities of the microlens planes with a resin having a second refractive index and planarizing the front surface, opposed to the microlens planes, of the resin, to form the planarized second optical resin layer, and the joining step is performed by joining the support layer to the planarized second optical resin layer. With this method, a microlens array excellent in surface accuracy and flatness can be produced without the need of provision of a support layer made from glass.