A microfluidic apparatus capable of being mounted on a rotation driving unit. When mounted on the rotation driving unit and rotated, a fluid flow is induced in the apparatus due to a centrifugal force. the microfluidic apparatus includes a sample supplying unit that comprises a sample chamber to house a sample and provides a fluid including a target material in which fine beads are bound to a target cell in the sample; a density-gradient separation unit that houses a density gradient material with a lower density than the target material, and receives the fluid from the sample supplying unit to separate the target material from the fluid based on a density difference; a fluid supplying channel connecting the sample supplying unit to the density-gradient separation unit to form a passage of the fluid; and a fluid supplying valve provided to the fluid supplying channel to selectively allow a flow of the fluid.