noun
General term for a device that filters liquids or gases. Can refer to kitchen strainers, laboratory filters, or industrial filtration equipment.
コーヒーを入れる前に、濾過器で水をこした。
Before making coffee, I filtered the water with a strainer.
この実験では、特殊な濾過器を使います。
In this experiment, we use a special filter.
Compound of 濾過 (roka, 'filtration') + 器 (ki, 'device'). 濾過 is from 濾 (ro, 'filter') + 過 (ka, 'pass through').