Disclosed is an electrostatic image developer containing colored resin particles containing a binder resin and a colorant, and an external additive, wherein, as the external additive, the electrostatic image developer contains plate-shaped zinc oxide fine particles having an average longer length of 50 to 2,000 nm and a value S of 0.0001 to 0.03 nm−1, which is a value obtained by dividing an average thickness d of the particles by an average base area A of the particles, and a content of the plate-shaped zinc oxide fine particles is in the range from 0.05 to 1 part by mass, with respect to 100 parts by mass of the colored resin particles.