PURPOSE: To obtain the stable retention of the electrostatic charge amount whose distribution is narrow and adequate when making toner by constituting this agent of a polymer in which a polymer chain having a monomer unit expressed by a specific formula and a polymer chain selected among a group made of a styrene-based polymer chain or the like are bonded in the graft-shape and/or block-shape.

CONSTITUTION: This electrostatic charge-controlling agent is constituted of polymer in which the polymer chain having the monomer unit expressed by the formula and the polymer chain selected among a group composed of the styrene-based polymer chain, a polyolefine-based polymer chain, a polyester- based polymer chain, an epoxy-based polymer chain and an urethane-based polymer chain are bonded in the graft-shape and/or block-shape. In the formula, Y represents a functional group selected among a group composed of OH, O, COOH, COO, NH2 and NH, and M represents boron or a 2 to 4-valence metal element, Z represents a 2-valence organic group, (n) represents integral numbers 0 to 2, X+ represents cation and Ar represents 1 to 3 pieces of alkyl group (1 to 18C)-substitutional benzene ring or the like.