A disk drive for driving a disk is disclosed, which includes: a driving unit configured to provide a driving force onto the disk, a main circuit pattern electrically connected with the driving unit, a sensor unit configured to sense a rotation speed of the disk, a first board supporting the sensor unit, a second board supporting the first board, and a base plate supporting the second board and the driving unit. One of the first board and the second board can be a flexible board electrically connecting the sensor unit with the main circuit pattern, and the other of the first board and the second board can be a rigid board. This disk drive can be utilized to ensure the distance between the sensor unit and the disk required for a rotation sensor to measure the rotation speed of the disk.