According to one embodiment, a disk device includes a housing and a sealing board fixed to a base of the housing. The base includes a through-hole and an installation surface formed around the through-hole. One of a first principal surface of the sealing board and the installation surface includes a projection formed therein. The sealing board is fixed to the installation surface by an adhesive material provided on an outer side of the projection with respect to the through-hole with the first principal surface or the installation surface abutting against the projection.