The endoscope filtration device for preprocessor of the present invention, the introduction portion for introducing a fluid, deriving unit that derives the fluid, said body portion flow path is formed which connects introducing portion and the said outlet portion, the flow path provided, the filter unit for filtering the fluid flowing through the flow channel, and the channel is provided between the said filter portion to the outlet portion, the fluid only in the direction toward the lead-out portion from the filter unit first check valve to pass, including.