To provide the operation method of a dust collector for an arc furnace, for sufficiently responding to the whole amount of exhaust gas containing powder dust discharged from the arc furnace, even when backwashing of one bag filter container in a plurality of bag filter containers is started, in a state of not adding an excess load on the rest of filter containers (in a number equal to (the whole number of the plurality of filter container)-1), and by which each bag filter can be designed into a compact volume and can be made at a low cost.

The operation method of a dust collector for an arc furnace is characterized in that: a backwashing period of a bag filter in each bag filter container of the collector is determined by avoiding a period when a powder dust density of exhaust gas produced when a material is fed to the arc furnace is high; and a bag filter in a bag filter container of the plurality of bag filter containers is subjected to backwashing in a period when the power dust density of the exhaust gas decreases and by decreasing a gas transportation amount compared to a gas transportation amount in the period when the power dust density of exhaust gas is high.