To improve flatness of a glass substrate 3 where a plurality of through electrodes 7 are formed.

A method of manufacturing a glass substrate with a through electrode comprises: a through hole forming step S1 for forming a plurality of through holes 4 for electrodes and a plurality of dummy through holes 5 on a plate-like glass 1; an electrode insertion step S2 for inserting an electrode member 6 into the through hole 4 for electrodes; a welding sep S3 for heating the plate-like glass 1 to a temperature higher than its softening point and welding the plate-like glass 1 and the electrode member 6; and a grinding sep S4 for forming a plurality of through electrodes 7 that are mutually and electrically separated by exposing the electrode member 6 to both surfaces of the plate-like glass 1 by grinding both surfaces of the plate-like glass 1 together with the electrode member 6.