A position indicator, comprising: a cylindrical casing; a core body disposed within the casing such that a tip of the core body projects from an opening at one end of the casing; a printed board disposed within the casing, a circuit element for detecting pressing force applied to the tip of the core body, the circuit element being disposed on the printed board; a board holder having a mounting portion for mounting the printed board; and a pen pressure detecting module formed by arranging a plurality of parts for detecting a displacement of the core body in an axial direction of the casing, the displacement corresponding to the pressing force applied to the tip in the axial direction, the plurality of parts being arranged within a hollow portion of a cylindrical holder portion of the board holder housed within a hollow portion of the casing such that an axial direction of the cylindrical holder portion coincides with the axial direction of the casing; wherein the holder portion has an opening portion in a portion of a side circumferential surface of the holder portion, the opening portion being opened in a direction perpendicular to the axial direction of the holder portion, at least one of the plurality of parts of the pen pressure detecting module is housed into the hollow portion of the cylindrical holder portion in the direction perpendicular to the axial direction of the holder portion through the opening portion, and the holder portion includes a locking portion configured to prevent the at least one of the plurality of parts from falling out through the opening portion characterized in that a flat surface is formed along the axial direction in a portion of the side circumferential surface of the holder portion, wherein the portion of the side circumferential surface of the holder portion is opposed to the opening portion with an axial position interposed between the portion of the side circumferential surface of the holder portion and the opening portion, so that the board holder does not roll, when the board holder is mounted on a flat surface of a workbench such that the flat surface formed in the portion of the side circumferential surface of the holder portion faces the flat surface of the workbench. a cylindrical casing; a core body disposed within the casing such that a tip of the core body projects from an opening at one end of the casing; a printed board disposed within the casing, a circuit element for detecting pressing force applied to the tip of the core body, the circuit element being disposed on the printed board; a board holder having a mounting portion for mounting the printed board; and a pen pressure detecting module formed by arranging a plurality of parts for detecting a displacement of the core body in an axial direction of the casing, the displacement corresponding to the pressing force applied to the tip in the axial direction, the plurality of parts being arranged within a hollow portion of a cylindrical holder portion of the board holder housed within a hollow portion of the casing such that an axial direction of the cylindrical holder portion coincides with the axial direction of the casing; wherein the holder portion has an opening portion in a portion of a side circumferential surface of the holder portion, the opening portion being opened in a direction perpendicular to the axial direction of the holder portion, at least one of the plurality of parts of the pen pressure detecting module is housed into the hollow portion of the cylindrical holder portion in the direction perpendicular to the axial direction of the holder portion through the opening portion, and the holder portion includes a locking portion configured to prevent the at least one of the plurality of parts from falling out through the opening portion characterized in that a flat surface is formed along the axial direction in a portion of the side circumferential surface of the holder portion, wherein the portion of the side circumferential surface of the holder portion is opposed to the opening portion with an axial position interposed between the portion of the side circumferential surface of the holder portion and the opening portion, so that the board holder does not roll, when the board holder is mounted on a flat surface of a workbench such that the flat surface formed in the portion of the side circumferential surface of the holder portion faces the flat surface of the workbench.