Disclosed is an inspection probe of an inspection system that includes an ultrasonic probe that is freely movable on a test object and irradiates the test object with an ultrasonic wave to detect a reflected wave, and a calculation unit that executes arithmetic processing according to a detection result according to the ultrasonic probe to acquire a flaw detection result of the test object. The inspection probe includes a chassis that is freely movable on a sheet material where a two-dimensional pattern disposed on the test object and indicating a position on the test object is drawn. The ultrasonic probe is fixed to the chassis so that an incident point of an ultrasonic wave that is incident onto an opposing surface of the test object from the ultrasonic probe is within an angle of view of the reader which reads the two-dimensional pattern.