Electrostatic latent images are developed with a toner in such a configuration that an electrostatic-latent-image-bearing member is disposed to face a developer-bearing member which bears thereon a developer consisting of a magnetic carrier and a toner by relatively moving the developer-bearing member and the electrostatic-latent-image-bearing member at different velocities, with the development being carried out under conditions represented by formula (1): 0.1 ⁢   ⁢ mm ≤ k = L · [ ( Vr / Vp ) - 1 ] ≤ 2 ⁢   ⁢ mm ( 1 ) wherein Vp is a transporting velocity (mm/sec) of the surface of the electrostatic-latent-image-bearing member, Vr is a transporting velocity (mm/sec) of the surface of the developer-bearing member, and L is a width (mm) of a contact portion between the developer and the electrostatic-latent-image-bearing member.