Provided is an electronic pen including a tubular housing having an opening at one end, a core body portion including a rod-shaped core body and a pressure member that holds a rear end of the core body and transmits a force applied to the core body, a writing pressure detector that detects a writing pressure applied to the core body, and a tubular holding member that accommodates and holds the core body portion. At least part of a side surface of the core body portion includes a flat surface portion parallel to an axial direction of the pen. An inner edge of the holding member has a cylindrical shape and at least part of the inner edge includes a protruding portion. With the core body portion mounted in the housing, the flat surface portion of the core body portion and the protruding portion of the holding member face each other.