Abstract: A method of controlling a magnetic disc apparatus. When a format writing is performed on a designated track portion, information of the location of the latest format writing record is read out from a control table storing information of the locations of the records of the format writings performed already to be compared with the information of location of the designated track portion where the format writing is to be currently performed. In dependence on the result of the comparison, it is decided whether erasing operation for the remaining track portions following the designated one is necessary or not. When decision is such that the erasure is necessary, erasing operation is performed for the remaining track portion in succession to the format writing on the designated track portion. Otherwise, the erasing operation is not performed for the remaining track portion, and information of the location of the record resulting from the format writing is subsequently stored in the control table.