According to one embodiment, a humidity control filter used in a magnetic recording/reproducing apparatus includes a housing that houses a magnetic recording medium and disposed inside the housing and close to a vent connecting the inside of the housing and outside air. The humidity control filter including a water-repellency coating having ventilation, a first adsorption layer of a porous solid having characteristics of type III isotherm according to IUPAC classification, and a second adsorption layer of a porous solid having characteristics represented by type I adsorption isotherm according to the IUPAC classification, which are provided in order from the vent.