抄録
Dust particles in a plasma are charged either negatively or positively and are subject to various types of forces in a plasma, including a drag force by plasma particles and a force due to collective nature of a plasma. Dust particles are found in layers in ground experiments balanced dominantly by the gravitational force and the electric force, while dust particles in the gravitation-free environment form three dimensional structures subject mainly to forces of ion/neutral drag and the electric field. Dynamic motion of fine particles in a complex (dust) plasma is reviewed with the emphasis of collective nature of plasmas.