AIR CLEANER

An air cleaner capable of, even when a flow rate of air flow flowing in the air cleaner is high, performing flow rate measurement with high measurement accuracy via an air flow sensor attached to an outlet pipe is provided. The above problem can be solved by an air cleaner including a plurality of ribs disposed at an inner surface of a housing defining a clean-side air chamber , the plurality of ribs extending from a corner portion of the housing, the corner portion being distant from a filter element and an outlet pipe , toward the filter element and the outlet pipe and terminating short of a surface of the housing with the outlet pipe provided, the plurality of ribs being configured such that a distance d between adjacent ribs narrows toward the outlet pipe