A filter device includes a casing having an inlet for introducing fluid and an outlet for discharging fluid, and a filtering element disposed between the inlet and the outlet. The filtering element has an outer circumference face restricted from being deformed in a fluid flowing direction. The filtering element has an upstream end face on an upstream side in the fluid flowing direction, and a downstream end face on a downstream side in the fluid flowing direction. The filtering element is configured to be compressed toward the upstream end face by pressing the downstream end face.