To enhance the spectral characteristics, transparency and image quality of a yellow toner fixed image after toner fixation by using a yellow developer consisting of a yellow toner contg. a specified compd. and a carrier.

This yellow developer consists of a yellow toner contg. a compd. of the formula and a carrier. A bonding resin used in the yellow toner is preferably colorless and transparent. A styrene resin, a satd. or unsatd. polyester resin or an epoxy resin is preferably used as the bonding resin. Two or more bonding resins may be used in combination. The glass transition temp. of the bonding resin is preferably ≥50°C in thermal analysis by DSC from the viewpoint of the preservability of the toner. The amt. of the compd. of the formula in the toner is preferably 0.1-30 pts.wt., in particular 2-15 pts.wt. based on 100 pts.wt. bonding resin.