Disclosed is a yarn winder capable of suppressing the expansion of a balloon of yarn unwound from a yarn accumulating unit and capable of binding fluff of the yarn. An upper end portion of a yarn accumulating drum (27) has a curved surface portion (65) having a circular curved surface shape of which diameter becomes smaller closer to the upper end, and an annular member (66) is disposed on the curved surface portion (65). The annular member (66) is composed of a sheet-like elastic material such as rubber of which thickness is smaller than the difference between the inner radius and the outer radius, and is in surface contact with the curved surface portion (65) over the entire circumference since the end adjacent to the inner circumference is elastically deformed along the curved surface portion (65). Yarn (Y) unwound from the yarn accumulating drum (27) passes between the curved surface portion (65) and the annular member (66), and is sent toward a winding unit. That is, the yarn (Y) is interposed between the curved surface portion (65) and the annular member (66).
