A mother substrate cutting method for cutting a plurality of unit substrates out of a mother substrate, comprises the steps of: (a) forming scribe lines on the mother substrate by scribe forming means; and (b) breaking the mother substrate along the scribe lines, wherein the step (a) includes a step of forming a first scribe line for cutting a first unit substrate out of the mother substrate and a second scribe line for cutting a second unit substrate out of the mother substrate by moving a pressure position to the mother substrate without a pressure to the mother substrate by the scribe forming means being interrupted.