A sample introduction device for introducing a sample into a sample chamber of a charged particle beam instrument , said sample introduction device comprising: a sample holder ; an insertion tube extending toward the sample chamber and rotatable about the axis of the tube ; a pre-evacuation chamber inside the insertion tube for performing a pre-evacuation; a partition valve for isolating said pre-evacuation chamber and said sample chamber from each other, said partition valve opened and closed by rotation of the insertion tube ; a goniometer for rotating said insertion tube and sample holder ; said sample holder linearly movable within the insertion tube having a sample holding portion capable of holding the sample (S); and a linearly movable support portion for supporting the sample holder ; mechanical drives for moving the support portion such that the sample holding portion moves from inside the pre-evacuation chamber into the sample chamber , characterised in that the sample introduction device further comprises a controller for controlling said mechanical drives and the goniometer ; wherein the controller is configured to perform an operation for controllably rotating the goniometer to open or close the partition valve , an operation for causing the mechanical drives to move said support portion such that the sample holding portion moves from inside the pre-evacuation chamber into the sample chamber , and an operation for causing the mechanical drives to move the support portion away from the sample holder , and wherein said mechanical drives and said controller are configured, when a first force (f1) is applied to said sample holder by a pressure difference between the interior of said sample chamber and the outside, to apply a second force (f2) to the sample holder , which second force (f2) is opposite in sense to and smaller than the first force (f1). a sample holder ; an insertion tube extending toward the sample chamber and rotatable about the axis of the tube ; a pre-evacuation chamber inside the insertion tube for performing a pre-evacuation; a partition valve for isolating said pre-evacuation chamber and said sample chamber from each other, said partition valve opened and closed by rotation of the insertion tube ; a goniometer for rotating said insertion tube and sample holder ; said sample holder linearly movable within the insertion tube having a sample holding portion capable of holding the sample (S); and a linearly movable support portion for supporting the sample holder ; mechanical drives for moving the support portion such that the sample holding portion moves from inside the pre-evacuation chamber into the sample chamber , characterised in that the sample introduction device further comprises a controller for controlling said mechanical drives and the goniometer ; wherein the controller is configured to perform an operation for controllably rotating the goniometer to open or close the partition valve , an operation for causing the mechanical drives to move said support portion such that the sample holding portion moves from inside the pre-evacuation chamber into the sample chamber , and an operation for causing the mechanical drives to move the support portion away from the sample holder , and wherein said mechanical drives and said controller are configured, when a first force (f1) is applied to said sample holder by a pressure difference between the interior of said sample chamber and the outside, to apply a second force (f2) to the sample holder , which second force (f2) is opposite in sense to and smaller than the first force (f1). <EOS>