To provide a foreign substance inspection device capable of preventing thinned chips to be laminated from cracking due to a foreign substance present on an upper surface of a processing object, when a semiconductor device is manufactured by laminating the chips.

According to an embodiment, a foreign substance inspection device 20 includes: a detection head 22 having a base inspection section 221 and a supporting section 222 for supporting the base inspection section 221; and a control unit 23 having a base data storage section 233, an inspection control section 232, and a foreign substance presence determining section 234. The base data storage section 233 stores base data including a base layout area indicating a layout position of a wiring substrate 80 or a chip of the uppermost layer of the wiring substrate 80. The inspection control section 232 controls the detection head 22 so as to be pressed by predetermined force while contacting with a predetermined position on an inspection object. The foreign substance presence determining section 234 extracts an area in which pressure is increased as compared with surroundings of the base layout area as a foreign substance presence area, by referring to the base data, from inspection data obtained by the base inspection section 221.