Method for manufacturing glass sheet

A method of manufacturing a glass sheet, the method comprising:

• an initial crack forming step of forming an initial crack on a first surface of a mother glass sheet;
• and
• a laser irradiation step of irradiating the mother glass sheet with laser light to cause a crack to propagate along a preset cleaving line through use of the initial crack as a starting point,
• wherein in the initial crack forming step, the initial crack is formed on the first surface at only a cleaving start point of the preset cleaving line,
• wherein the laser irradiation step comprises irradiating a second surface of the mother glass sheet, which is opposite to the first surface, with the laser light to heat a surface layer and an inner portion of the second surface, to thereby cause, through a thermal shock caused by the heating, the crack to propagate in an entire thickness direction of the mother glass sheet while propagating along the preset cleaving line,
• wherein the preset cleaving line also has a cleaving end point where the initial crack is not present on the first surface, and
• wherein the laser irradiation step comprises irradiating the second surface of the mother glass sheet with the laser light starting at a position on the second surface that is opposite to a location of the initial crack on the first surface, and then irradiating the second surface of the mother glass sheet along the preset cleaving line beyond an end of the initial crack on the first surface to the cleaving end point.