A spinning reel for forwardly casting a fishing line, comprising: a reel body unit; a spool shaft having a distal end and being supported by the reel body unit so as to be movable longitudinally; a spool including a line winding cylinder part having a front side, and a front flange disposed on the front side of the line winding cylinder part and being attached to the spool shaft, the line winding cylinder part being configured to have the fishing line wound to an outside thereof; a drag mechanism comprising a braking member housed inside of the spool and being configured to brake a rotation of the spool, and a drag adjuster attached to the distal end of the spool shaft and being configured to adjust a frictional coupling force of the braking member; and a seal member having a drag adjuster side and being configured to be elastically deformed, the seal member protruding from the drag adjuster side toward the front flange so as to seal a space formed between the front flange and the drag adjuster, and being configured to abut the front flange when the drag adjuster is operated, wherein the drag adjuster comprises an adjustment knob screwed into a distal end of the spool shaft, an abutting member disposed in the adjustment knob and being configured to abut a front surface of the seal member, and a fixing member fixing the abutting member to the adjustment knob, characterized in that the fixing member comprises a threaded portion and a head portion, the adjustment knob comprises a boss portion to which the threaded portion is screwed, and the abutting member comprises a holding portion into which the boss portion is inserted and that is held by the adjustment knob and the head portion. a reel body unit; a spool shaft having a distal end and being supported by the reel body unit so as to be movable longitudinally; a spool including a line winding cylinder part having a front side, and a front flange disposed on the front side of the line winding cylinder part and being attached to the spool shaft, the line winding cylinder part being configured to have the fishing line wound to an outside thereof; a drag mechanism comprising a braking member housed inside of the spool and being configured to brake a rotation of the spool, and a drag adjuster attached to the distal end of the spool shaft and being configured to adjust a frictional coupling force of the braking member; and a seal member having a drag adjuster side and being configured to be elastically deformed, the seal member protruding from the drag adjuster side toward the front flange so as to seal a space formed between the front flange and the drag adjuster, and being configured to abut the front flange when the drag adjuster is operated, wherein the drag adjuster comprises an adjustment knob screwed into a distal end of the spool shaft, an abutting member disposed in the adjustment knob and being configured to abut a front surface of the seal member, and a fixing member fixing the abutting member to the adjustment knob, characterized in that the fixing member comprises a threaded portion and a head portion, the adjustment knob comprises a boss portion to which the threaded portion is screwed, and the abutting member comprises a holding portion into which the boss portion is inserted and that is held by the adjustment knob and the head portion.