The present invention has been directed to a method of semiconductor manufacturing apparatus and the particle monitor, a semiconductor manufacturing apparatus of the present invention is incident from the chamber to conduct a predetermined semiconductor process, and the light source for the incident light to the interior of the chamber, the light scattering sensing light, and the light receiving unit to measure the scattered light intensity value, and a first controller that determines the magnitude of the reference value has already been set and the scattered light intensity value, the second controller for determining the progress whether for the semiconductor process, It characterized by comprising. Method of particle monitor the invention comprises the steps of joining the laser beam proceeds the semiconductor process, in parallel manner, and measuring the intensity of light value scattering from the incident light, compared to the reference value for the scattering intensity of light value has already been set If step, the scattered light intensity value that is greater than the reference value characterized in that it comprises the step of interlocking the semiconductor process. Semiconductor, wafer, and particles, laser light, a light receiving portion, the sensor