The invention relates to an optical substance manipulator capable of continuing to apply a continued force of action to moving substances without being limited by the flowing conditions for the substances yet with a wide manipulation margin and with efficiency, thereby continuously carrying out various manipulations such as separation, concentration, mixing, and deflection. Specifically, the invention provides an optical substance manipulator capable of manipulating microscopic particles dispersed in a flowing fluid by means of light pressure, characterized by comprising an optical system that forms multiple linear light-collective areas simultaneously with respect to a fluid that flows on a subject surface (5), and further comprising, in optical paths forming the respective linear light-collective areas, means (CL1), (CL2) adapted to adjust directions of the linear light-collective areas on the subject surface and means (M1), (M2) adapted to adjust positions of the linear light-collective areas.