In a disk drive device having a double cover structure with low-density gas enclosed therein, embodiments of the present invention allow a more reliable leak inspection to be performed on the second cover and to prevent defects caused by joining the secondary cover. An HDD according to an embodiment of the present invention comprises a ventilation path from a ventilation hole on an inner cover to a space between the inner cover and an outer cover. An outer peripheral end of an adhesive layer is apart from a joining section, which is exposed in the space. Helium gas flowing out of the ventilation hole flows to the space via the ventilation path and remains within the space. This enables detection of leakage of the helium gas from the joining section to be performed more easily.