A motorized working apparatus includes a housing having an air inlet, an air guide leading from the air inlet into the housing, and an air filter which is curved hood-shaped outwardly and covers the air inlet of the housing. The air filter includes a filter frame body with a filter-fabric-free air outlet face facing the air inlet of the housing and with a window frame structure protruding over the filter-fabric-free air outlet face and having at least one window region. A filter fabric occupies the at least one window region, and a fixation releasably fixes the filter frame body to the housing. The window frame structure has frame webs which delimit the at least one window region and which protrude relative to the filter fabric towards an air supply side in the at least one window region and include web side edges which run sloping at an obtuse angle relative to adjacent window planes, and/or the fixation includes a pre-fixing clamping holding arrangement and a final fixing holding arrangement which are independent of each other, and/or the window frame structure of the air filter protrudes over the filter-fabric-free air outlet face in the shape of a roof with a triangular cross-sectional form.