1. A method for microscopy of several samples using optical microscopy and particle beam microscopy, comprising: a) dividing the samples into a partial quantity and a residual quantity, b) preparing the samples of the partial quantity such that they contain registration marks which are visible in both optical microscopy and particle beam microscopy, c) imaging the samples of the partial quantity using optical microscopy and particle beam microscopy, with the result that a pair consisting of optical microscopy image and particle beam microscopy image is obtained for each sample of the partial quantity, d) positioning registering pairs consisting of an optical microscopy image and a particle beam microscopy image relative to each other using the registration marks, e) modifying the optical microscopy images and the particle beam microscopy images of the position-registered pairs by removing the registration marks from the images, f) training a registration algorithm which evaluates image contents and issues a quality measure for a position registration of each of the pairs using the modified optical microscopy images and the modified particle beam microscopy images of the position-registered pairs, and g) imaging the samples of the residual quantity having no registration marks using optical microscopy and particle beam microscopy, with the result that a pair including an optical microscopy image and a particle beam microscopy image is also obtained for each sample of the residual quantity, and position-registering these pairs relative to each other with the help of the trained registration algorithm by moving the images of each pair opposite one another to maximize the quality measure issued by the trained registration algorithm for the respective pair.