A fishing reel in which a spool is rotatably supported by a main body includes a frame, a right side cover and a left side cover. The fishing reel is characterized in that an auxiliary cover for protecting the finger and thumb of the user of the reel from a flat winding mechanism, or/and an auxiliary cover for improving the manipulating property of the reel are provided on both side covers between them. In addition, one end portion of each of the auxiliary covers, which is located where the spool is inserted into and pulled out of the frame, is removably engaged with one side plate of the frame, so that the auxiliary cover is prevented from coming off the side plate. Further, the other end portion of each of the auxiliary covers is engaged with the side cover located outside the other side plate of the frame.