Cleaning device and cleaning performance maintaining method

A cleaning performance maintaining method for a cleaning device including a cleaning blade, a support section to support the cleaning blade while pressing an end portion of the cleaning blade to a cleaning object surface, a container which has an opening portion at a side opposite to the cleaning object surface and contains a removal object scraped from the cleaning object surface by the cleaning blade, and an elastic sheet one end of which is fixed to a peripheral portion of the opening portion of the container, the other end of which is in contact with a non-opposite surface as a surface of the cleaning blade at a side not opposite to the cleaning object surface, and which guides the removal object scraped from the cleaning object surface by the cleaning blade into the container, comprising:

• causing a slope-shaped portion, which is provided on at least a part of a surface of the elastic sheet opposite to the cleaning blade and has a side surface inclined to both the non-opposite surface and the surface of the elastic sheet opposite to the cleaning blade in a state of contact with the non-opposite surface, to lie between the cleaning blade and the elastic sheet and preventing surface contact between the cleaning blade and the elastic sheet.