To provide a clutch mechanism for imparting different yield strength according to a driving passage of driving force without hindering size reduction and cost reduction in an apparatus with a built-in driving mechanism for internally storing the driving mechanism for transmitting the driving force of a motor to a driven part via a gear train and a camera as one example of such an apparatus with the built-in driving mechanism.

A planetary mechanism is arranged in a transmission passage of the driving force of the reciprocally rotatable motor, two sun gears 2211 and 2212 fitted with mutual clutch surfaces are arranged in the planetary mechanism, and the clutch surfaces 2211b and 2212b composed of the continuity of a crest and a trough are arranged so that the yield strength is made different according to the rotational direction.