A retainer member (70) has a retainer portion (72,73), a through hole (74), and non-circular cross section (77). A bearing section (55) is disposed on an outer periphery of the retainer portion (72,73). The through hole (74) has a circular axial cross section and an inner periphery, which is axially penetrated by a non-circular portion (15b) of a spool shaft (15) from back to front. The non-circular cross-sectional portion (77) is formed by cutting out a front end of the retainer portion (72) by machining. The non-circular cross-sectional portion (77) has a non-circular axial cross section that engages the non-circular portion (15b) of the spool shaft.