A filter device is configured to filter a sample containing a liquid component and plural solid components mixed with the liquid component. The filter device includes a filter part, and a capturing-retaining mechanism. The filter part is configured to capture the solid components and to allow the liquid component to pass through the filter part. The capturing-retaining mechanism is configured to prevent the captured solid components from being removed from the filter part when the sample passes through the filter part. The filter device has high filter performance.
