A scanning transmission electron microscope which enhances correction accuracy of a de-scanning coil for canceling a transmitted-electron-beam position change on an electron detector. Here, this transmitted-electron-beam position change appears in accompaniment with a primary-electron-beam position change on a specimen caused by a scanning coil. First, control over the scanning coil is digitized. Moreover, while being synchronized with a digital control signal resulting from this digitization, values in a de-scanning table registered in a FM(2) are outputted to the de-scanning coil. Here, the de-scanning table is created as follows: Diffraction images before and after activating the scanning coil and the de-scanning coil are photographed using a camera. Then, based on a result acquired by analyzing a resultant displacement quantity of the diffraction images by the image processing, the de-scanning table is created.