Filtration apparatus and electronic device

An electronic device, comprising:

• a housing body having an inner surface and an outer surface opposite to the inner surface and at least one function hole that extends through the inner surface and the outer surface of the housing body;
• a waterproof assembly positioned on at least one function hole, the waterproof assembly being configured to prevent liquid from passing through the underlying at least one function hole;
• and
• a filtration apparatus, comprising:
• a first filter layer positioned on an outer side of the outer surface, the first filter layer covering at least one function hole, and a plurality of first mesh holes provided at intervals on the first filter layer;
• and
• a second filter layer positioned between the outer surface and the first filter layer, the second filter layer covering at least one function hole, and a plurality of second mesh holes provided at intervals on the second filter layer, wherein in a cross-section parallel to the first filter layer, a cross-section area of the first mesh hole is greater than a cross-section area of the second mesh hole.