To provide a rotational motion control device which can stably maintain rotation brake characteristics with resistance capable of easily adjusting continuous variables without a maintenance for a long term, and to provide a camera platform.

A rotary electric machine includes: a rotor having multiple permanent magnets disposed in a rotation direction by setting an N pole and an S pole alternatively; a stator core having a predetermined number of teeth protruded in a radial direction opposite to the rotor arranged in a circumferential direction by keeping predetermined interval; coils wound to the teeth; and a stator having angle detection means to output signals according to a rotation angle of the rotor. The rotary electric machine controls, with resistance, so that a rotational motion of the rotor is attenuated, by means of rotation brake control means which is being electrically connected to the outside of the rotary electric machine.