A fluid filter has a filter housing with inlet opening for fluid to be cleaned and outlet opening for cleaned fluid. A filter element arranged in an element receptacle of the filter housing separates inlet opening from outlet opening. The filter housing has a housing body with an installation opening to the element receptacle, through which the filter element in an installation direction is introduced into the element receptacle. The filter housing has a housing cover for closing the installation opening. The installation opening is arranged in a transverse side of the housing body that is lateral relative to the housing axis. The filter housing has a sealing surface, surrounding the housing axis at least partially circumferentially, for contacting a seal of the filter element. The filter element has a seal support device for the seal and the filter housing has a pressing device for the seal support device.