An objective is to provide a toner product with which the difference between the water content of a toner in a toner container and the water content of another toner present in an image forming apparatus is minimized, and a sharp charging amount distribution can be obtained to form high-quality images; and also to provide an image forming method thereof. Also disclosed is a toner product in which a toner is stored in a toner container, wherein the toner possesses a toner particle having an amount of a carboxyl group present on a surface of the toner particle, being 1.0.times.10.sup.-7-2.5.times.10.sup.-5 mol/g, and the toner container is made of a resin containing polyethylene terephthalate, the amount of the carboxyl group determined via titration employing a strongly basic solution as a titration reagent after dispersing the toner in water.