Abstract: An embodiment of a semiconductor manufacturing device includes a chamber to perform a predetermined semiconductor process, a light source to emit light into the chamber, a light receiver to sense scattered light emitted from the light source and to measure an intensity of the scattered light, a first controller to compare the measured intensity of the scattered light with a preset reference value, and a second controller to determine whether to perform the predetermined semiconductor process based on the intensity of the scattered light. An embodiment of the particle monitoring method includes emitting laser light into a process chamber simultaneously with performing a semiconductor process, measuring an intensity of a scattered light after being emitted, comparing the measured intensity of the scattered light with a preset reference value, and interlocking the semiconductor process when the measured intensity of the scattered light is larger than the preset reference value.