Ventilation hole waterproof structure of on-board component

A ventilation hole waterproof structure of an on-board component mounted on a vehicle, comprising:

• an on-board component main body that includes:
• a housing defining an inside and an outside of the housing;
• a ventilation hole provided to the housing to extend through the housing such that the ventilation hole provides communication between the inside and the outside of the housing;
• and
• a waterproof filter provided at a position that corresponds to the ventilation hole;
• and
• an attachment member that has a connecting part connected to the on-board component main body, the attachment member being fixed to a body of the vehicle, wherein:
• the attachment member has an attachment surface that extends from at least an upper end of the connecting part downwardly in a vertical direction;
• the housing has a connecting surface, which is connected to the connecting part of the attachment member, and which is opposed to the attachment surface of the attachment member with a clearance formed between the connecting surface and the attachment surface;
• the ventilation hole has an outside opening that opens at an external wall surface of the housing, which wall surface is opposed to the attachment surface;
• and
• the waterproof filter is fixed to the external wall surface of the housing by heat fusion such that the waterproof filter covers the outside opening of the ventilation hole.