Provided is a two-component developer having excellent developing performance and little change in image concentration, and achieving long-term suppression of image defects such as transfer failure and fogging.Provided is a two-component developer containing a magnetic carrier and a toner, wherein the magnetic carrier has magnetic carrier particles comprising a silicone resin B coated on the surfaces of filled core particles in which pores of porous magnetic core particles are filled with a silicone resin A, the silicone resin A is a silicone resin cured in the presence of a non-metal catalyst or without a catalyst, while the silicone resin B is a silicone resin cured in the presence of a metal catalyst having titanium or zirconium, and the toner contains a binder resin, a release agent and a colorant, and has an average circularity of 0.940 or more.