To prevent swell of adhesive from a sleeve spigot part, with respect to a developing roller being join/fixed with the adhesive by forcibly fitting a flange in the sleeve.

As for this developing roller, chamfer 14a is applied on a peripheral end part of the rear end side in the direction of forcibly fitting the disk shape flange 14 into the sleeve 13. On the periphery of the flange, plural lines of grooves along the forcibly fitting direction, are formed connecting to the chamfer 14a. The depth (d) of the respective groove 14b is, made shallower than the difference D of the sleeve spigot part 13a. At the time of join/fixing the flange 14 in the sleeve 13, the adhesive is applied to the groove 14b through a counter gap C formed by the chamfer 14a, after flushing by forcibly fitting the flange in the spigot part 13a.