An oscillation device axially oscillates a spool with handle rotation, and includes a driving gear, a cam gear, a slider, and a guiding portion. The driving gear is arranged on a master gear shaft, so as to be spaced apart from the master gear. The cam gear has a cam pin on its side surface, and is arranged on the fishing rod attachment side of the oscillation device relative to the master gear shaft. The cam gear is attached to the reel unit rotatably about an axis substantially parallel to the master gear shaft, so as to rotate in cooperation with the driving gear. The slider has a cam receiving portion engaging with the cam pin of the cam gear, and is axially immovably attached to the rear of the spool shaft. The guiding portion is provided in the reel unit and guides the slider movably in the axial direction.