A cutting machine of the present invention for cutting a material to be cut, which is placed on a table, with a rotating saw blade, includes an imaging device, a determination device and a stopping device. The imaging device takes a video image of an area on the table and outputs the video image. The determination device makes a determination on whether or not a number of pixels of a specific color, which is previously set, exceeds a predetermined threshold in one frame of image constituting the video image outputted from the imaging device. The stopping device stops rotation of the saw blade when it is determined by the determination device that the number of pixels of the specific color exceeds the predetermined threshold.