To provide an optical mechanism capable of suppressing power consumption by efficiently controlling a driving motor in charge operation when high-speed operation is not required.

The optical mechanism includes: a charge means 7 that charges an biasing mechanism 8a of a movable mirror 21 reciprocating between a first position arranged on an optical path of a photographic optical system and a second position for retreat from the optical path of the photographic optical system, or a mechanical shutter 30 adjusting exposure time of an imaging device; a motor 3 that generates driving force from rotation in a first direction in a first period from start of charge by the charge means until releasing of the charge by the charge means; transmission mechanisms 3a, 4 and 5 that transmit the driving force to the charge means; and a control part 15 that can select any one of a first motor sequence for driving the motor by first electric energy in the first period and a second motor sequence for driving the motor by second electric energy smaller than the first electric energy in the first period.