To provide a window glass cover which can easily be attached by even one person when it is used, which can be folded compactly when it is stored, and which can combinedly be used for windows of an automobile and a house, in the window glass cover which prevents a temperature rise by sunlight by covering a window glass from outside and prevents the freezing of the window glass by cold air.

A window glass cover includes: a cover body, on which creases of a bellows shape are provided in the lateral direction; extension members extended from both right and left ends of the cover body; and fixing members which are provided near the ends of the extension members and can be attached detachably to the inside of the window glass. The window glass cover, which can combinedly be used for windows of an automobile and a house, further has: a bellows width adjusting member made up of cords, holes through which the cords are passed, and stoppers which adjust the length of the straps on the cover body; and a storage member provided at the either one end of the extension member and made up of a band and buttons capable of retaining the folded bellows as it is in a stored state.