Abstract: Disclosed is an air purifier. The air purifier includes an outer housing assembly, an outer side filter element and an inner side filter element. The outer housing assembly defines a mounting cavity, and the outer housing assembly is provided with air inlet holes communicated with the mounting cavity. The outer side filter element is disposed in the mounting cavity. The inner side filter element includes a high efficiency particulate air (HEPA) layer and an activated carbon layer, and the inner side filter element is disposed on a radial inner side of the outer side filter element. The outer side filter element can be separately detached.