A fishing spinning reel (100, 300, 500, 700), comprising: a reel unit (1, 101, 101A to 101C, 301, 401, 600, 701); and a rotor (2, 302, 502, 702) rotatably supported by the reel unit (1, 101, 101A to 101C, 301, 401, 600, 701), wherein the reel unit (1, 101, 101A to 101C, 301, 401, 600, 701) includes: a body (10, 110, 310, 410, 510, 610, 710, 810) having a side opening portion (13, 113, 113A to 113C, 313, 513, 713) and in which a spool reciprocating device (70, 370, 480, 570, 680, 770, 880) is housed and supported; a lid (30, 130, 130A to 130D, 330, 430, 530, 730) closing the side opening portion (13, 113, 113A to 113C, 313, 513, 713); and a cover member (40, 340, 440, 540, 640, 740, 840) mounted on a rear portion of the body (10, 110, 310, 410, 510, 610, 710, 810), wherein a handle shaft (5, 305, 405, 505, 605, 705) is rotatably supported by the body (10, 110, 310, 410, 510, 610, 710, 810) and the lid (30, 130, 130A to 130D, 330, 430, 530, 730), in the rear portion of the body (10, 110, 310, 410, 510, 610, 710, 810), a rear opening portion (15, 315, 415, 515, 715, 815) for receiving at least a part of a component of the spool reciprocating device (70, 370, 480, 570, 680, 770, 880) and disposing the component on the rear side is formed, and the cover member (40, 340, 440, 540, 640, 740, 840) covers the rear opening portion (15, 315, 415, 515, 715, 815) and the component, wherein the body (10, 110, 310, 410, 510, 610, 710, 810) has a bridge portion (14, 314, 514, 714) extending between the side opening portion (13, 113, 113A to 113C, 313, 513, 713) and the rear opening portion (15, 315, 415, 515, 715, 815) and forms edges of apertures of the side opening portion (13, 113, 113A to 113C, 313, 513, 713) and the rear opening portion (15, 315, 415, 515, 715, 815), the fishing spinning reel (100, 300, 500, 700) being characterized in that the side opening portion (13, 113, 113A to 113C, 313, 513, 713) and the lid (30, 130, 130A to 130D, 330, 430, 530, 730) are formed in circular shapes. a reel unit (1, 101, 101A to 101C, 301, 401, 600, 701); and a rotor (2, 302, 502, 702) rotatably supported by the reel unit (1, 101, 101A to 101C, 301, 401, 600, 701), wherein the reel unit (1, 101, 101A to 101C, 301, 401, 600, 701) includes: a body (10, 110, 310, 410, 510, 610, 710, 810) having a side opening portion (13, 113, 113A to 113C, 313, 513, 713) and in which a spool reciprocating device (70, 370, 480, 570, 680, 770, 880) is housed and supported; a lid (30, 130, 130A to 130D, 330, 430, 530, 730) closing the side opening portion (13, 113, 113A to 113C, 313, 513, 713); and a cover member (40, 340, 440, 540, 640, 740, 840) mounted on a rear portion of the body (10, 110, 310, 410, 510, 610, 710, 810), wherein a handle shaft (5, 305, 405, 505, 605, 705) is rotatably supported by the body (10, 110, 310, 410, 510, 610, 710, 810) and the lid (30, 130, 130A to 130D, 330, 430, 530, 730), in the rear portion of the body (10, 110, 310, 410, 510, 610, 710, 810), a rear opening portion (15, 315, 415, 515, 715, 815) for receiving at least a part of a component of the spool reciprocating device (70, 370, 480, 570, 680, 770, 880) and disposing the component on the rear side is formed, and the cover member (40, 340, 440, 540, 640, 740, 840) covers the rear opening portion (15, 315, 415, 515, 715, 815) and the component, wherein the body (10, 110, 310, 410, 510, 610, 710, 810) has a bridge portion (14, 314, 514, 714) extending between the side opening portion (13, 113, 113A to 113C, 313, 513, 713) and the rear opening portion (15, 315, 415, 515, 715, 815) and forms edges of apertures of the side opening portion (13, 113, 113A to 113C, 313, 513, 713) and the rear opening portion (15, 315, 415, 515, 715, 815), the fishing spinning reel (100, 300, 500, 700) being characterized in that the side opening portion (13, 113, 113A to 113C, 313, 513, 713) and the lid (30, 130, 130A to 130D, 330, 430, 530, 730) are formed in circular shapes. a body (10, 110, 310, 410, 510, 610, 710, 810) having a side opening portion (13, 113, 113A to 113C, 313, 513, 713) and in which a spool reciprocating device (70, 370, 480, 570, 680, 770, 880) is housed and supported; a lid (30, 130, 130A to 130D, 330, 430, 530, 730) closing the side opening portion (13, 113, 113A to 113C, 313, 513, 713); and a cover member (40, 340, 440, 540, 640, 740, 840) mounted on a rear portion of the body (10, 110, 310, 410, 510, 610, 710, 810), wherein a handle shaft (5, 305, 405, 505, 605, 705) is rotatably supported by the body (10, 110, 310, 410, 510, 610, 710, 810) and the lid (30, 130, 130A to 130D, 330, 430, 530, 730), in the rear portion of the body (10, 110, 310, 410, 510, 610, 710, 810), a rear opening portion (15, 315, 415, 515, 715, 815) for receiving at least a part of a component of the spool reciprocating device (70, 370, 480, 570, 680, 770, 880) and disposing the component on the rear side is formed, and the cover member (40, 340, 440, 540, 640, 740, 840) covers the rear opening portion (15, 315, 415, 515, 715, 815) and the component, wherein the body (10, 110, 310, 410, 510, 610, 710, 810) has a bridge portion (14, 314, 514, 714) extending between the side opening portion (13, 113, 113A to 113C, 313, 513, 713) and the rear opening portion (15, 315, 415, 515, 715, 815) and forms edges of apertures of the side opening portion (13, 113, 113A to 113C, 313, 513, 713) and the rear opening portion (15, 315, 415, 515, 715, 815), the fishing spinning reel (100, 300, 500, 700) being characterized in that the side opening portion (13, 113, 113A to 113C, 313, 513, 713) and the lid (30, 130, 130A to 130D, 330, 430, 530, 730) are formed in circular shapes.