An image forming apparatus includes image carrier carrying latent image, developer carrier supplying developer on the image carrier, transfer part transferring the developer on the image carrier, cleaning blade removing attachment that attaches to a surface of the image carrier, internal environment detection part detecting an internal environmental temperature in the apparatus, developer disposal control part controlling disposal of developer from the developer carrier to the image carrier, and voltage control part controlling an applied voltage to the transfer part. Wherein, the developer disposal control part determines an absolute value of the applied voltage larger, which is applied to the transfer part during disposing the developer, where the internal environment temperature is high, and the voltage control part controls the applied voltage to the transfer part based on the absolute value of the voltage decided by the developer disposal control part.