The image forming apparatus includes image forming device for forming a toner image on a recording material, a residual toner collecting container detachably provided on a main body of said image forming apparatus and adapted to collect residual toner discharged from said image forming means, said residual toner collecting container being capable of collecting the residual toner through an opening at a side of said container, and regulation means for preventing said containing container from being attached onto or removed from the main body of said image forming apparatus until the opening of said collecting container is directed upwardly in a gravitational direction and an inclined angle of said collecting container exceeds a set angle. It can prevent from flowing out through the opening more positively.