There is provided a sample operation apparatus in which, by a static electricity force acting between a probe and a sample, an accurate position is gripped without the sample being moved, and the sample can be operated by the probe for an observation, a grip, a release, or the like. In a casing body capable of being sealed, there are installed a sample operation tweezers comprising an observation probe and a grip probe, and a sample base fixing a substrate on which the sample is mounted. By the facts that a surface of the substrate is treated such that its hydrophilic nature is higher than the sample operation tweezers, and that a humidity in the casing body is controlled by a humidity control device, there is made such that an actuation of a grip, a movement, a separation or the like of the sample is performed under a state in which water films are formed on the sample, the substrate and a surface of the sample operation tweezers.