To obtain a developer for developing an electrostatic latent image without causing the fogging of an image and the scattering of the toner in an image forming process repeated over a long period of time and stably giving a high density clear image.

This developer is a two-component developer consisting of a carrier and a toner. The carrier is obtd. by coating the surfaces of magnetic particles with polyolefin resin having ≥90°C heat absorption start temp. and 126-133°C heat absorption peak tamp. measured by differential thermal analysis. The bonding resin of the toner is polyester resin having 25-80KOHmg/g acid value.