A spool brake device for a dual-bearing reel is provided. The spool brake device is configured to apply a braking force to a spool. The brake device includes a conductor, a magnet, and a braking force adjusting unit. The magnet is configured to move along an axial direction of a spool shaft of the spool with respect to the reel unit and face the conductor in a radial direction relative to the axis of the spool shaft. The braking force adjusting unit is configured to adjust the braking force which is applied to the spool by a magnetic force acting on the conductor when the conductor is rotated, in such a way to change magnetic fluxes acting on the conductor by changing an axially facing range between the conductor and the magnet according to the movement of the magnet along the axial direction relative to the reel unit.