Patent ID: 8741526

Claim:
A developer comprising: toner particles; and an insulating liquid, wherein a fatty acid ester is contained as the insulating liquid, a substance A expressed by the following formula (1) and a substance B expressed by the following formula (2) are further contained, R—O AO n H (1) where R is a phenyl group, a styrylated phenyl group, an α-naphthyl group, or a β-naphthyl group, A is an alkylene group, and n is an integer of at least 1, where R is an organic group having a carbon number of at least 1 and no more than 15, and n is an integer of at least 1 and no more than 3, and the total percentage in which substance A and substance B are contained is at least 0.1 wt % and no more than 3.0 wt %.