An image forming apparatus suppresses the deposition of transfer-residual toner on a sealing sheet and also suppresses the dropping of deposited toner therefrom, at a high temperature and in a high humidity environment. The apparatus includes a photosensitive drum, a cleaning blade for removing toner, a housing portion for housing the toner removed by the cleaning blade, and a sealing sheet for preventing the leakage of toner and performs charge elimination upstream of the sealing sheet in the direction of movement of the photosensitive drum, wherein a work function difference between the sealing sheet and the photosensitive drum is equal to or greater than 0.25 eV.