An image forming apparatus to which a toner replenishing container is detachable, the toner replenishing container comprising: a toner storing section (120Y, 120M, 120C, 120K) which stores toner; a toner replenishing member for supplying the toner from said toner storing section to a developing section (90Y, 90M, 90C, 90K); wherein the image forming apparatus comprises: a detecting section for detecting information about an environment in the apparatus; and a controller for determining information relating to the amount of toner stored in said toner storing section; characterized in that the controller is configured to determine information relating to toner replenishing operation in accordance with the information about the amount of toner stored in said toner storing section and information about the environment in the apparatus, the information relating to toner replenishment operation including a toner replenishing amount per unit rotation of said toner replenishing member and a number of times of operation of said toner replenishing member on the basis of the toner replenishing amount per unit rotation; and the controller is configured to control operation of said toner replenishing member on the basis of the information relating to a toner replenishing operation. a toner storing section (120Y, 120M, 120C, 120K) which stores toner; a toner replenishing member for supplying the toner from said toner storing section to a developing section (90Y, 90M, 90C, 90K); wherein the image forming apparatus comprises: a detecting section for detecting information about an environment in the apparatus; and a controller for determining information relating to the amount of toner stored in said toner storing section; characterized in that the controller is configured to determine information relating to toner replenishing operation in accordance with the information about the amount of toner stored in said toner storing section and information about the environment in the apparatus, the information relating to toner replenishment operation including a toner replenishing amount per unit rotation of said toner replenishing member and a number of times of operation of said toner replenishing member on the basis of the toner replenishing amount per unit rotation; and the controller is configured to control operation of said toner replenishing member on the basis of the information relating to a toner replenishing operation. a detecting section for detecting information about an environment in the apparatus; and a controller for determining information relating to the amount of toner stored in said toner storing section; characterized in that the controller is configured to determine information relating to toner replenishing operation in accordance with the information about the amount of toner stored in said toner storing section and information about the environment in the apparatus, the information relating to toner replenishment operation including a toner replenishing amount per unit rotation of said toner replenishing member and a number of times of operation of said toner replenishing member on the basis of the toner replenishing amount per unit rotation; and the controller is configured to control operation of said toner replenishing member on the basis of the information relating to a toner replenishing operation.