Method of producing threaded member, method of producing spark plug, and apparatus for producing threaded member

A threaded member production apparatus comprising:

• a holding mechanism that holds a workpiece having a first portion which extends in a direction of a center axis of the workpiece and on which a male thread is to be rolled and a second portion whose length in a direction perpendicular to the center axis is longer than that of the first portion;
• and
• two rolling dies used to roll a male thread on an outer circumference of the first portion with the workpiece held by the holding mechanism, wherein
• the holding mechanism holds the workpiece such that at least a first portion center axis that is a part of the center axis and corresponds to the first portion is separated in a prescribed direction from a first virtual plane that contains center axes of the two rolling dies and such that, in the workpiece held, the distance of the first portion center axis from the first virtual plane increases with distance from the second portion.