Abstract: A headrest of the type formed by a foaming process of placing a generally "M" shaped headrest frame having a pair of stay portions in a three-dimensional bag-like trim cover assembly, then injecting a liquid foaming base material into within the trim cover assembly and creating a foam padding therewithin together with the headrest frame and trim cover assembly, with the two stay portions projecting outwardly from one side of the trim cover assembly via the respective two through-holes. The headrest has an opening formed in that one side of trim cover assembly where the two through-holes lie. The opening is disposed between the two through-holes and has a small width relative to a width of the same two through-holes, thereby minimizing the possibility that the liquid foaming base material will be leaked from the opening during the foaming process.