The device for conveying and separating a suspension with biological cells or micro-organisms in biological processes has a rotating separating element in a surrounding reaction space with a flow space which is in the form of a rotational gap, an inlet opening, an inner outlet opening for the cell-free medium, an outer through opening and an exit opening for the suspension. The distance R4 of the exit opening from the axis of rotation is greater than the distance R1 of the inlet opening, and the distance R3 of the through opening is greater than the distance R2 of the inner outlet opening. The suspension can thus be conveyed in the flow space and the cells efficiently separated at the same time. The device is particularly suitable for continuous operation with sensitive mammal cells.