Abstract: The filter device has a high-temperature filter medium and a low-temperature filter medium. The high-temperature filter medium includes a high-temperature resin that melts above a first melting-temperature. The low-temperature filter medium includes a low-temperature resin which melts above a second melting-temperature which is lower than the first melting-temperature. The low-temperature filter medium is disposed in a layer in which a temperature for forming a welded portion is hard to rise. In the welded portion, both the high-temperature resin and the low-temperature resin are welded. A welding step supplies heat so that heat is transferred from the high-temperature filter medium to the low-temperature filter medium. In the welding step, melted resins are cured to form the welded portion after melting both the high-temperature resin and the low-temperature resin.

Abstract: 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.

Abstract: ABSTRACT OF THE DISCLOSURE 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.