To make the operation of a filtering and dust collecting equipment for a long time possible in a method for cleaning the filtering and dust collecting equipment for suppressing clogging of a filter fabric caused by muddy ash content and in exhaust gas treatment using the filtering and dust collecting equipment.

Exhaust gas is treated by removing the ash content in the exhaust gas by means of the filtering and dust collecting equipment 8 after calcium hydroxide is fed into the exhaust gas containing hydrogen chloride gas. While the treatment of the exhaust gas is suspended, grain and powder such as sand are carried under pressure into the filtering and dust collecting equipment 8 from the filtration direction. Then, deposit stuck on the above filter fabric 9 is peeled off and fallen down to perform cleaning.