Provided is a sheet for container to be used in a flexible container, the sheet for container having a plurality of films layered in the sheet for container, the sheet for container including: a first film including a first base-material layer, which is coated with a first applying-type gas barrier layer and made of a single type of material having a heat-sealing property; and a second film including a second base-material layer, which is coated with a second applying-type gas barrier layer and made of a single type of material that is a same type of material as the first base-material layer, in which: the first film and the second film are attached to each other by heat sealing; and a gas enclosing portion, which is partially non-attached and in which gas is able to be enclosed, is formed between the first film and the second film.