The present invention provides a method of manufacturing a spark plug which is capable of securing a bonding strength at the middle of a chip while suppressing an occurrence of scattering. The method of manufacturing the spark plug having a ground electrode to which a bonding surface of a chip is welded, has a machining process of machining the ground electrode such that an area located inside an edge of a welding-planned part where the chip is welded on the ground electrode and including a center of the welding-planned part is rougher than a section except the area of the welding-planned part, and a bonding process of bonding the chip to the welding-planned part of the ground electrode after undergoing the machining process by resistance welding.