To provide a bearing mounting structure for a manual operation device capable of mounting a shaft of a driver and its bearing member onto a base easily without possibility of dropping off.

In a bearing mounting structure wherein a shaft 51 of a drive lever 5 pivotally supported by a base 3 and its bearing member 53 are mounted onto a notch 37 of the base 3, a holding part 53a of the bearing member 53 is fitted into a fitting hole 37a, by fitting the holding part 53a with the shaft 51 inserted into the fitting hole 37a from an aperture side of the notch 37 through an entrance groove 37b at the outside of the shaft 51 from its axially outer side. In this state, the bearing member 53 is appropriately rotated via a rotation lever 53e, for example, so as to have an inner engaging part 53c of the bearing member 53 face an inner surface of the base 3 and have an outer engaging part 53d of the bearing member 53 face an outer surface of the base 3. Moreover, the entrance groove 37b of the notch 37 is formed to be narrower in width than the holding part 53a of the bearing member 53.