Disclosed are a magnetic toner for developing an electrostatic latent image comprising magnetic toner particles containing a binder resin of 100 parts by weight and a magnetic substance of 20 to 150 parts by weight, and an apparatus unit and an image forming method for employing the magnetic toner. A frictional electrification property is such that the absolute value of the frictional electrification amount relative to an iron powder of 250 mesh-pass to 350 mesh-on is 25 to 40 mc/kg. Assuming that for particle distribution of the magnetic toner a weight-average particle diameter (D.sub.4) for the magnetic toner is X (.mu.m) and that a count % in a count distribution of magnetic toner particles that have a diameter of 3.17 .mu.m or smaller is Y (%), expressions (1) and (2) are satisfied:-5X+35.ltoreq.Y.ltoreq.-25X+180 (1)3.5.ltoreq.X.ltoreq.6.5 (2).Sphericity (.psi.) of particles is equal to or greater than 0.80 and a product (.sigma..sub.r .times.H.sub.c) of remanence �.sigma..sub.r (Am.sup.2 /kg)! and coercive force (H.sub.c (kA/m)! of the magnetic substance in a magnetic field of 795.8 kA/m (10 k oersted) is 10 to 56 (kA.sup.2 m/kg).