a filter device for the insertion of filter elements to be positioned in a filter housing having a filter inlet and a filter outlet for the fluid to be filtered . the filter elements are traversed in both directions for filtration or backwashing . certain filter elements perform the filtration in a filtration position and at least one additional filter element can be backwashed in a backwashing position to clean its active filtration surface . as the individual filter elements are brought into the backwashing position and are then returned to their filtration position in succession by a pivoting device , the filter elements are individually displaced into the backwashing position in a temporal sequence , in contrast to prior art , where an arm - type backwashing device is pivoted towards the individual filter elements to carry out the backwashing process .