The invention relates to the field of filtration equipment. The invention provides a filter capable of filtering particles to purify air and improve air quality. The following main technical solution is adopted: the filter comprises a filtration element and filtration structures. The filtration element comprises a first end and a second end opposite to each other, and the first end is provided with an air inlet, while the second end is provided with air outlets. Each filtration structure comprises a first flow guide groove formed in a wall of the air inlet and a second flow guide groove formed in a wall of each air outlet, and at least one portion of the first flow guide groove is opposite to the second flow guide groove in a direction from the first end to the second end. Particularly, the portions, in which the first flow guide grooves are opposite to the second flow guide grooves in the direction from the first end to the second end, of the filtration element are made of a metal fiber felt. The filter provided by the invention is capable of filtering particles in exhaust from motor vehicles, such as diesel vehicles or gasoline vehicles.