The present invention relates to a container (2) for purifying water by utilization of sunlight, comprising a first surface (4, 8&prime；, 9&prime；, 10&prime；, 12&prime；) that is formed of a permeable layer for sunlight and a second surface (6, 8&Prime；, 9&Prime；, 10&Prime；, 12&Prime；) that is formed of an absorbing layer for sunlight. Further, the container comprises a first opening (14) and a second opening (16), respectively, provided with filter elements (18, 19). Filling with water is intended to be done in the first opening (14) and discharge of water is intended to be done through the second opening (16) after the water in the container (2) has been heated to a temperature of at least 600 C after exposure by sunlight and also exposure of ultraviolet radiation in order to make it possible to kill undesired micro-organisms.
