A toner for developing an electrostatic image is disclosed. The toner particles containing a binder resin containing a polyester resin or a polyol resin and a colorant, and the toner particles contain aluminum in an amount of 0.007 to 0.140% by weight, chlorine in an amount of 0.002 to 0.412% by weight, and the toner particles have an average circular degree of 0.94 to 0.99 and an average circle equivalent diameter of from 2.6 to 7.4 .mu.m.