Abstract: A protective case for use with a diver's face mask of the type which includes a glass window, a pliable frame supporting the window around its periphery, and a headband attached to opposite sides of the frame. The protective case comprises: (a) a flat base panel of foam material and (b) a peripheral wall attached to and upstanding from the edge of the base panel and having a contour with the base panel adapted to house the mask without play therebetween. There is (c) a flat cover panel of foam material attached on one side of the peripheral wall with a pair of spaced tethers, and (d) a fastener for detachably attaching the other side of the cover panel to the peripheral wall.