A novel element, a novel formation method of a film, or a novel formation method of an element is provided. Alternatively, a film including graphene is formed at low cost and high yield. A formation method of a film including graphene includes a first step of forming a film including graphene oxide that includes a first region and a second region by application of a dispersion liquid in which graphene oxide is dispersed over a substrate and removal of dispersion medium from the applied dispersion liquid, a second step of forming a film including graphene by light irradiation to the first region to reduce the first region, and a third step of removing the second region by washing.