It is an object of the invention that development quality is improved by increasing the amount of charge during the transportation of toner by a toner holding member and decreasing the amount of charge during development for rendering an electrostatic latent image visible. A one-component non-magnetic toner is supplied from a toner supplying unit to the toner holding member such that the toner is electrostatically attracted to adhere to the toner holding member with a large amount of charge. The charge of the toner under transportation is reduced by charge adjusting means such as a conductive roller supplied with a potential from a frictional charging member or a voltage source, whereby the amount of development or the amount of toner adhering to an electrostatic latent image is increased and development quality is improved.