Image forming apparatus and control method thereof

An image forming apparatus, comprising:

• image forming means, for forming an image on a recording medium with toner, having a discharge portion for permitting discharge of toner;
• a first container capable of containing the toner conveyed from the discharge portion;
• a second container removable from said image forming apparatus and capable of containing the toner conveyed from said first container;
• stop means for stopping a conveyance of the toner from said first container to said second container;
• toner amount detection means for detecting an amount of the toner contained in said first container;
• and
• determination means for determining an image forming operation on the basis of a detection result of said detection means when the conveyance of the toner from said first container to said second container is stopped,
• wherein when said second container is removed from said image forming apparatus, said image forming apparatus is capable of forming an image on the basis of a detection result of said toner amount detection means in a state in which the conveyance of the toner from said first container to said second container is stopped.