Abstract: A foldable glass substrate includes a top surface, a bottom surface, and a side surface. The side surface includes a first side surface extending at a first angle from the top surface, a second side surface extending at a second angle from the bottom surface, and a third side surface extending from each of the first side surface and the second side surface. A length of the third side surface in a direction substantially perpendicular to at least one of the top surface and the bottom surface is equal to or greater than about 0.3 times and equal to or less than about 0.7 times of a minimum distance between the top surface and the bottom surface. The minimum distance is equal to or greater than about 15 micrometers (?m) and equal to or less than about 100 ?m.