The invention relates to a scraper bar apparatus that is intended for scraping of material, which exists in a fluid basin (N), to an exhaust arrangement (2), such as one or more surface chutes (2a), bottom chutes (2b) or like that exists in connection with the fluid basin, by means of a scraper bar arrangement (1), which moves in the liquid basin. The scraper bar apparatus includes an endless power transmission assembly (3), such as one or more chains (3'), wire ropes, ropes and/or like, that surrounds the area (N') to be treated of the fluid basin (N) and that is arranged during an operational situation to rotate (w) along the periphery (N's) of the area to be treated by means of controlling (3'') and operating means and, whereto there has been attached a scraper bar arrangement (1; 1') by its opposite ends (x1, x2), which, while rotating (w) in the fluid basin, such as a clarification basin, flotation basin and/or like in one or more essentially horizontal planes (p, b), performs scraping in the fluid basin all over the desired area to be treated (N').