The invention first relates to an air filter attachment (4) for a turbomachine, in particular a side channel compressor, comprising a housing, comprising a filter material (8) arranged in a housing interior, and comprising an inlet (9) and an outlet (10) which are formed in the housing, which have a free opening cross section, and through which air is suctioned. The aim of the invention is to advantageously design a turbomachine comprising an air filter attachment. This is achieved in that the housing interior that has the filter material (8) extends laterally relative to the opening cross section of the inlet (9) and/or the outlet (10) in a non-uniform manner and in any case in a direction by a magnitude of 1½ or more times the dimension from a central axis (M) of the respective opening cross section to a periphery of the opening cross section in the direction. The invention further relates to a turbomachine, in particular a side channel compressor, comprising such an air filter attachment. Additionally, the invention relates to a filter part (12, 19) consisting of a pleated filter material (8) or a circumferential filter wall (21) which is connected to a base part (22) and which consists of a filter material.