A developer capable of providing an excellent image without causing a
charging failure even after a long-term and repeated use contains a toner
particle having a binder resin and a colorant, an inorganic fine
particle, and a conductive fine particle, in which a volume average
particle diameter Da of the conductive fine particle and an number
average primary particle diameter Db of the inorganic fine particle
satisfy the expression (1) below, and a rate of liberation "a" of the
conductive fine particle from the toner particle is 40 to 95% and a rate
of liberation "b" of the inorganic fine particle from the toner particle
is 0.1 to 5% Da.gtoreq.10Db. (1)