A first shroud and a second shroud are opposed to the peripheral end surface of a recording disk at a certain constant distance. The second shroud is spaced downstream from the first shroud in the direction of the rotation of the recording disk. A shroud plate is opposed to the peripheral end surface of the recording disk at a position between the first and second shrouds. The shroud plate functions as a shroud. The shroud plate serves to suppress turbulence of airflow. Vibration of the recording disk can be suppressed. Moreover, if the shroud plate is designed to extend along a virtual plane perpendicular to the rotation axis of the recording disk, the airflow is prevented from staying between the first and second shrouds. The airflow can effectively be taken out. The airflow can effectively be utilized.