To provide an electromotive circular saw processing apparatus capable of precisely cutting a long processing material in an extremely safe manner using an electromotive circular saw while looking the India ink line of the long processing material.

The electromotive circular saw processing apparatus is constituted of a circular saw guide 1 for guiding and sliding the electromotive circular saw A along a longitudinal direction to cut the processing material W along the India ink line and a base plate 3 having a guide rule 2, which guides the slide metal fittings 10 of the circular saw guide 1 along the longitudinal direction, provided to its one side and operated in connection with the circular saw guide 1 to hold the processing material W. The downward C-shaped slide metal fittings 10 are supported in a freely slidable manner so as to straddle the guide rule 2 and the circular saw guide 1 is closed so as to be superposed on the base plate 3 to allow the circular saw guide 1 and the base plate 3 to cooperate with each other to hold and process the processing material W.