A developing device includes a developer supporting member for supporting developer and a developer charging member disposed to face the developer supporting member for charging and supplying the developer to the developer supporting member. The developer supporting member has a surface having a calculated average surface roughness Ra between 0.1 .mu.m and 0.6 .mu.m and a surface free energy SFE between 15 mN/m and 26 mN/m. Further, the developer charging member has an Asker F hardness Haf between 24.degree. and 56.degree..