A gas sensor package includes a package substrate having a hole, the hole having an end that is opened at a first surface of the package substrate; a gas sensor disposed in the hole of the package substrate; a fixing plate disposed on the first surface of the package substrate, the fixing plate having a vent hole extending between a top surface and a bottom surface of the fixing plate, the bottom surface of the fixing plate facing toward the package substrate and the top surface of the fixing plate facing away from the package substrate, and the fixing plate overlapping the hole of the package substrate when viewed in a plan view; and a protective film attached to the fixing plate. The protective film overlaps the vent hole when viewed in a plan view.