ELECTROSTATIC CHARGE IMAGE DEVELOPING DEVELOPER

PROBLEM TO BE SOLVED: To provide an electrostatic charge image developing developer capable of retaining good image quality even by high-speed continuous printing. SOLUTION: This electrostatic charge image developing developer has toner particles containing at least a bonding resin and a chromium atom-containing compound. The developer is introduced into atmospheric microwave induced plasma of helium, the chromium and carbon atoms are excited and allowed to emit light and the intensity of the emitted light is measured with the lapse of time to obtain the emission spectrum of the chromium and carbon atoms in the developer. The absolute deviation of errors to an approximate line obtained on the basis of the emission spectrum and exhibiting the dispersed state of the chromium and carbon atoms is