Motorized retracting unit and motorized retractable rearview mirror

A motorized retracting unit (3) for a motorized retractable rearview mirror (1 ) for a vehicle includes a shaft holder (30) that has a main shaft (301), a gear case (31) that is rotatably mounted on the main shaft (301), a plate (32), and a transmission mechanism (35, 36) that transmits driving power of a motor (34) to the main shaft (301). The plate (32) includes a plate member (320), a shaft supporting member (321) that rotatably supports the main shaft (301), a motor mounting member (322) on which the motor (34) is mounted, and a flexible member (323, 328) that is provided between the shaft supporting member (321) and the motor mounting member (322), enabling a relative movement of the shaft supporting member (321) and the motor mounting member (322).