Method for manufacturing spark plug

A method for manufacturing a spark plug, the spark plug including a first electrode and a second electrode, the first electrode including a noble-metal-containing tip joined to an electrode base material, the second electrode opposed to a first surface of the tip with a spark gap interposed therebetween, the tip having a second surface on a side opposite the first surface, the method comprising:

• a pressing step of pressing the tip with a jig in a first direction from the first surface of the tip toward the second surface of the tip when the second surface of the tip is in contact with the electrode base material;
• and
• a welding step of welding the electrode base material to the tip being pressed by the jig, wherein
• the tip further has a side surface contiguous to the first surface and the second surface, and an edge at which the side surface and the first surface meet each other,
• the jig has a recessed portion to be brought into contact with the edge,
• the recessed portion has a diameter-decreasing portion having an inner dimension that gradually decreases in a second direction opposite to the first direction,
• a first end portion of the diameter-decreasing portion in the first direction having an inner dimension larger than an outer dimension of the edge, and a second end portion of the diameter-decreasing portion in the second direction having an inner dimension equal to the outer dimension of the edge, and,
• in the pressing step, the diameter-decreasing portion is brought into contact with at least a portion of the edge, and the tip is moved to a target position on the electrode base material to which the tip is to be welded.