A developing method, including the steps of: carrying one-component non-magnetic toner on a developer carrier; pressing the one-component non-magnetic toner by a regulating member so as to regulate a transporting quantity of the one-component non-magnetic toner so that the one-component non-magnetic toner is charged; forming an electrostatic latent image on an image carrier; providing the one-component non-magnetic toner to the electrostatic latent image so as to convert the electrostatic latent image into a visible toner image; and controlling the one-component non-magnetic toner so that the one-component non-magnetic toner pressed by the regulating member satisfies the following relationship: B/A1, where A represents a width [m] of a particle size distribution of the one-component non-magnetic toner; and B represents a width [fC] of a charge quantity distribution of the one-component non-magnetic toner.