A sheet glass that has a side surface with an average surface roughness equal to or less than 0.2 μm is provided. Furthermore, a method of manufacturing a sheet glass is provided that includes processing a base-material glass sheet to obtain a sheet glass that has a side surface with an average surface roughness equal to or less than 0.2 μm. Moreover, a method of manufacturing a sheet glass is provided that includes processing a base-material glass sheet so that an average surface roughness of a side surface becomes equal to or less than a predetermined value according to a section modulus of the sheet glass that is to be manufactured.