Disk device having ventilation structure between outside and inside

A disk device is disclosed in which an air inlet to an air passage for ventilation between inside and outside of the disk device is secured even when the upper or side surface of the housing of the disk device is closed, while at the same time suppressing the noises and vibrations originating from the disk device. A spindle motor for carrying at least a recording disk and an actuator for driving a carriage having a head for accessing the disk are mounted on the base of the housing. A cover is mounted on the base through a gasket thereby to hermetically seal the interior of the disk device. A ventilation structure is formed in the cover. This ventilation structure includes an air passage formed in the neighborhood of an edge of the cover, a filter-accommodating recess formed around the air passage, an air filter arranged in the filter-accommodating recess, an air passage formed through the base outside of the gasket of the disk device, a ventilation groove formed in the upper surface of the cover for securing communication between the filter-accommodating recess and the air passage, and a sealing member for covering the air passage on the upper surface of the cover.