Filter device for purifying a fluid, - having a filter element which can be flowed through by fluid, - having a filter housing for receiving the filter element, - having a valve member arranged displaceably in the filter housing and defining a valve member longitudinal axis, which valve member can be moved to and from in the context of a valve member movement between a closed position closing an overflow arrangement of the filter housing, in which the fluid cannot flow through the filter element, and at least one open position (45, 46) releasing the overflow arrangement, in which the filter element is in an operating position and is flowed through by fluid, wherein the filter housing comprises a mandrel for receiving the filter element and the valve member, wherein the filter element in the operating position is set on the mandrel, - having an actuating arrangement for actuating the valve member in the context of the valve member movement, wherein the actuating arrangement has an opener arrangement arranged at the valve member and an extension arrangement arranged at the filter element and the extension arrangement interacts with the opener arrangement in the operating position in order to bring the valve member into an open position (45, 46), - wherein the open arrangement comprises one or several opener pins arranged respectively at the valve member for actuating the valve member, characterized in that - the opener pins are plonked respectively through a pin body cutout and protrude laterally beyond the mandrel, wherein the pin body cutouts are arranged at the mandrel and pass through the mandrel in each case transversely with regard to a mandrel longitudinal axis. - having a filter element which can be flowed through by fluid, - having a filter housing for receiving the filter element, - having a valve member arranged displaceably in the filter housing and defining a valve member longitudinal axis, which valve member can be moved to and from in the context of a valve member movement between a closed position closing an overflow arrangement of the filter housing, in which the fluid cannot flow through the filter element, and at least one open position (45, 46) releasing the overflow arrangement, in which the filter element is in an operating position and is flowed through by fluid, wherein the filter housing comprises a mandrel for receiving the filter element and the valve member, wherein the filter element in the operating position is set on the mandrel, - having an actuating arrangement for actuating the valve member in the context of the valve member movement, wherein the actuating arrangement has an opener arrangement arranged at the valve member and an extension arrangement arranged at the filter element and the extension arrangement interacts with the opener arrangement in the operating position in order to bring the valve member into an open position (45, 46), - wherein the open arrangement comprises one or several opener pins arranged respectively at the valve member for actuating the valve member, characterized in that - the opener pins are plonked respectively through a pin body cutout and protrude laterally beyond the mandrel, wherein the pin body cutouts are arranged at the mandrel and pass through the mandrel in each case transversely with regard to a mandrel longitudinal axis.