PURPOSE: To obtain an electric charge controlling agent contg. no heavy metal, excellent in electrostatic charge kick-off characteristics, the extent of electrostatic charge, aging stability and environmental stability and exhibiting stable properties at the time of producing a toner by using specified arom. carboxylic acid as an effective component.

CONSTITUTION: Arom. carboxylic acid having ≥12 carbon atoms and at least two carboxyl groups capable of forming acid anhydride in each molecule is incorporated into a toner as an electric charge controlling agent. This arom. carboxylic acid having 12-20 carbon atoms of the arom. rings is used as the effective component of the electric charge controlling agent. Carboxylic acid or binaphthyl-carboxylic acid of a bicyclic uncondensed 6-membered arom. carbocyclic compd. having at least two carboxyl groups capable of forming acid anhydride in each molecule may be used as the arom. carboxylic acid.