Charge control agent and toner using same

The present invention provides a positive electrostatic charge control agent which contains, as active ingredients, one or more rhodanine compounds that are represented by general formula (1). (In the formula, R1 represents a hydrogen atom or the like; R2 represents a hydrogen atom or the like; R3-R7 may be the same as or different from each other, and each represents a hydrogen atom, a cyano group, a trifluoromethyl group, a nitro group, an optionally substituted linear or branched alkyl group having 1-8 carbon atoms, or the like; the R2-R7 moieties may combine together to form a ring; and V, W, X, Y and Z each represents a carbon atom or a nitrogen atom, with zero to three moieties among the V, W, X, Y and Z moieties being nitrogen atoms which do not have any substituent of the R3-R7 moieties. In this connection, at least one moiety among the R3-R7 moieties represents a cyano group, a nitro group or a linear or branched alkyl group having 1-4 carbon atoms, said linear or branched alkyl group being substitut