A cover for housing a portable electronic device that includes: a first main surface formed in a rectangular shape,
a second main surface formed in a rectangular shape on a side opposite to the first main surface, a peripheral edge surface that joins peripheral edge portions of the first main surface and the second main surface and has an upper edge surface, a lower edge surface, and a pair of side edge surfaces, at least one joystick that protrudes from the first main surface, operation portions that are provided on portions of the upper surface toward the pair of side edge surfaces and protrude toward the second main surface, and protruding portions that protrude from the second main surface and are located on the lower edge surface sides of the operation portions.