Provided is a mother ceramic substrate that, when divided into individual substrates (ceramic substrates), can be divided to cause divided end surfaces to be perpendicular to principal surfaces of the individual substrates, and that can provide ceramic substrates with high form accuracy; an individual ceramic substrate obtained from the mother ceramic substrate; a module component including the ceramic substrate; and a method of manufacturing a mother ceramic substrate. In a mother ceramic substrate that can be divided at a predetermined position and separated into a plurality of individual substrates, a dividing groove that defines a division position is formed in a principal surface on one side, and a protruding thread is formed on a principal surface on another side at a position corresponding to a position of the dividing groove formed in the principal surface on the one side in view in a thickness direction of the mother ceramic substrate.