PURPOSE: To make it possible to work timber having a length longer than the effective cutting length of the machine concerned by a method wherein the mounting part of a supporting frame, which is stationarily provided so as to workably support a holding means, to the table face side is arranged so as to part aside from the extension of a travelling slit.

CONSTITUTION: In case of worked timber W, which is longer than the effective cutting length of the travelling circular saw machine concerned, since a mounting part 29 is located left side the extension of a travelling slit 6, the left side edge of the worked timber W is set to be brought in line with the travelling slit or the cutting position. By travelling a circular saw 16 under the condition that the worked timber W is fixed to the table face by being pressed with a keep plate 30 in the above-mentioned state, the worked timber W can be cut in the effective working domain of the machine concerned. After the finish of working, the worked timber W is set by being turned upside down. By cutting the resultant worked timber W after the confirmation of the straightness of a part to be worked, the remaining part of the worked timber W can be cut. Accordingly, the cutting of the worked timber, which is longer than the effective cutting length, can be performed by two strokes.