A plasma processing method includes the steps of etching the target object with a CF-based processing gas by using a patterned resist film as a mask, removing deposits accumulated inside a processing chamber during the step of etching the target object by using a processing gas containing at least an O2 gas, and ashing the resist film by using a processing gas containing at least an O2 gas. Relevant places in the processing chamber from which the deposits are removed are heated in the step of removing the deposits.