The reel unit includes a chassis, a lid member, a guard member, a tubular part, and a screw member. The chassis includes a mechanism attachment space at a lateral side thereof, a first opening extending through a front edge of the chassis, and a second opening extending through a rear edge of the chassis. The guard member includes a boss being inserted into the second opening from the rear edge of the chassis. The guard member is attached to the chassis and the lid member from behind to cover the chassis and the lid member. The tubular part is disposed between the first opening and the second opening within the mechanism attachment space and arranged to be liquid-tight. The screw member passes through the first opening and being screwed into the boss. The screw member includes a head being held inside the tubular part.
