According to one embodiment, in a semiconductor storage device, a conductive cover is provided on a side of the principal surface, and covers at least a part of the memory and the controller. A substrate has a first notched portion and a second notched portion in an outer edge. The conductive cover has a top plate portion, a first side plate portion, a second side plate portion, a first claw portion, and a second claw portion. The first claw portion is extended from a lower end of the first side plate in a direction intersecting with the principal surface. The first claw portion is fitted into the first notched portion. The second claw portion is extended from a lower end of the second side plate in the direction intersecting with the principal surface. The second claw portion is fitted into the second notched portion.