A waterproof structure is provided on a spinning reel including a reel main body, a cylindrical member disposed on an outer periphery of a spool shaft and a rotor disposed at a front of the cylindrical member in the reel main body. The waterproof structure includes a seal member which waterproofs the entire circumference in the area between the cylindrical member and the rotor. The seal member includes a main lip that is in liquid-tight contact at a contact portion in the axial direction of the spool shaft. An annular wall portion is disposed on at least one of the rotor or the cylindrical member. The annular wall portion covers the contact portion at the entire circumference of an outer peripheral side of the contact portion.