A filter device, particularly an air breather filter device for venting a fuel tank, includes a housing with a first port provided as an inlet in normal operation of the filter device and a second port provided as an outlet under normal operation of the filter device. The housing encloses at least one filter and an air passage extends from the first port to the second port passing through the filter. Inside the housing a baffle unit is arranged in the housing for covering the at least one first filter in relation to the second port, wherein the baffle unit is arranged to deflect a fluid flow entering the filter device through the second port.