An object of the present invention is to provide a filtering device which makes it possible to obtain a chemical liquid having excellent performance and enables filter media to have sufficiently long pot life. Another object of the present invention is to provide a purification device, a chemical liquid manufacturing device, a filtered substance to be purified, a chemical liquid, and an actinic ray-sensitive or radiation-sensitive resin composition. A filtering device according to an embodiment of the present invention has a first filter unit including a first filter, which satisfies at least one condition selected from the group consisting of following conditions 1 to 3, and a housing accommodating the first filter and a second filter unit including a second filter different from the first filter and a housing accommodating the second filter, in which the first filter unit and the second filter unit are independently disposed in a pipe line through which a substance to be purified is supplied. Condition 1: the filter has a filter medium including two or more layers containing materials different from each other. Condition 2: the filter has a filter medium including two or more layers having different pore structures. Condition 3: the filter has a filter medium including one layer in which different materials are mixed together.