A developing apparatus includes: a developing sleeve that carries a mono-component developer; and a developing blade that abuts on the sleeve to regulate a layer thickness of the developer on the sleeve, wherein surface roughness parameters of the sleeve satisfy: 3.0≦Rpk≦9.0; and 2≦Pc2≦10. At an abutment portion between the sleeve and the blade, surface roughness parameters of the blade satisfy: 0.030≦Sm≦0.170; and 0.10≦Rvk×(100−Mr2)/100≦1.30, where Sm is a mean spacing of profile irregularities [mm]; Rpk is an initial wear height [μm]; Rvk is an oil retaining depth [μm]; Mr2 is a profile bearing length ratio 2 [%]; and Pc2 denotes the number of profile peaks having a height larger than a count level from a center line per the evaluation length of 1 mm.