Electronic pen

The purpose of the present invention is to achieve further thinning of an electronic pen without reducing the function of the electronic pen. A columnar ferrite core (212) has a through hole (212a) and is composed of three parts, namely a front part (212F), a middle part (212M) and a rear part (212B). The outer diameter of the middle part (212M) is shorter than the outer diameter of the front side part (212F) and the outer diameter of the rear side part (212B), so that the shape of the middle part (212M) becomes thinner as a so-called dumbbell as a gymnastic instrument. Since the coil (211) is formed by winding the insulated wire around the intermediate portion (212M), the portion of the ferrite core (212) around which the coil (211) is wound does not become thick, and the electronic pen can be made thinner. 本发明不使电子笔的功能下降地实现电子笔的进一步的细型化。柱状的铁氧体芯(212)具有贯通孔(212a)，并且由前侧部分(212F)、中间部分(212M)、后侧部分(212B)这三个部分构成。中间部分(212M)的外径比前侧部分(212F)的外径和后侧部分(212B)的外径短，从而如作为体操器械的所谓的哑铃那样成为了中间部分(212M)变细的形状。由于在中间部分(212M)卷绕绝缘导线而形成线圈(211)，