To provide a probe for scanning probe microscope which can be inserted into the very narrow groove, etc., of a semiconductor sample and can detect an interactive force between the probe and the internal surface of the sample, and a method for detecting the force that acts on the probe.

A probe for scanning probe microscope is provided with a supporting section 2, a probe section 4, and a detecting section 3 which is positioned between the supporting section 2 and the probe section 4 and detects an interactive force between the probe section 4 and a sample, with the detecting section 3 and the probe section 4 being substantially formed on the same axis. Since the detecting section 3 and the probe section 4 are formed on the same axis, the spatial restriction to the probe section 4 becomes smaller and the section 4 can be inserted into the very narrow groove, etc., of the sample. When the probe is excited to make torsional resonant motions and the change of the torsionally vibrating state of the probe which occurs when a force acts on the probe section 4 is detected, the interactive force between he section 4 and the sample can be detected with high sensitivity.