Abstract: A toner which can exhibit 5 nN or less of inter-particle force calculated by the following equation (1) when the toner is laminated and carried on a toner carrier:Fv=q.multidot.E-Fi (1)where Fv is an inter-particle force, q.multidot.E is a Coulomb force calculated by the following equation:q.multidot.E=q.multidot.{Vb+(Q/M).multidot..delta..multidot.P.multidot.dt.s ub.1.sup.2 /(2.epsilon.o.epsilon..sub.T)}/(.epsilon..sub.T .multidot.g+dt.sub.1) (2)where Fi is an image-force calculated by the following equation (3):Fi={(W.sub.1 .multidot..pi.d.sup.3 .multidot..delta.)/(6 .epsilon.o .epsilon..sub.T)}.multidot.(Q/M).sup.2 (3)where q is a quantity of charge [C] of the toner particle to be developed, E is an electric field strength [V/m] acting on the toner layer, Q/M is a toner charge-to-mass ratio [mC/g], W.sub.1 is an amount of toner separated by development among the toner laminated and carried on the toner carrier, .epsilon.o is a vacuum dielectric constant [C/(V.multidot.m)], .epsilon..sub.