Patent Number: 
Section: claims

1. A specimen holder support device for use with an electron microscope having a wall defining a vacuum tight specimen chamber, said specimen holder support device comprising: a cylindrical support member extending through said wall in an x direction and mounted to said wall;  a spherical bearing surface formed on an inner surface of said support member;  a generally cylindrical swinging member having a cylindrical bearing on an outer surface inserted in said support member and swingable about said spherical bearing in Y and Z directions perpendicular to each other and the X direction;  a specimen holder slidably mounted in said swinging member via an O-ring and having a front end extending inwardly beyond said spherical bearing surfaces;  an X-motion drive mechanism engaging with the front end of said specimen holder; and  a specimen holder movement-arresting means spring biasing said specimen holder relative to said swinging member for alleviating force applied to said X-motion drive mechanism from said specimen holder when a vacuum is pulled on said chamber. 2. The specimen holder support device of  claim 1 , wherein said holder movement-arresting means is mounted to an outer surface of said swinging member and connected to said specimen holder via a hole formed in said outer surface, and wherein said specimen holder is biased away from said specimen chamber by said holder movement-arresting means. claim 1 3. The specimen holder support device of  claim 2 , wherein a means for detecting axial position of said specimen holder is mounted to said holder movement-arresting means. claim 2 4. A specimen holder support device for use with an electron microscope having a wall defining a specimen chamber whose interior is maintained as a vacuum, said specimen holder support device comprising: a holder mounting member having a spherical bearing supported to said wall defining said specimen chamber, a swinging member having an inner end rotatably held by said spherical bearing, a holder-receiving hole formed in said swinging member and acting to place the interior of said specimen chamber in communication with outside, and a slider-receiving groove formed in an outer-end portion of said swinging member axially of said swinging member;  a specimen holder held in said holder-receiving hole slidably and hermetically and having an inner-end portion and a guide pin, said inner-end portion having a specimen holding portion for holding a specimen, said inner-end portion being positioned in said specimen chamber, said guide pin being mounted on an outer surface of an outer-end portion located outside said wall defining said specimen chamber, said guide pin protruding into said slider-receiving groove;  a holder inner end-positioning drive mechanism abutting against the specimen holding portion of said specimen holder to place said specimen holding portion in position axially of said swinging member;  a slider received in said slider-receiving groove so as to be movable axially of said swinging member and having a pin engagement portion and a movement-arresting portion shaped to protrude outwardly from said swinging member, said pin engagement portion engaging with the guide pin of said specimen holder;  a slider-arresting member having a slider-arresting portion for coming into engagement with said movement-arresting portion of said slider from a side of an inner end of said holder mounting member; and  a spring for biasing said slider-arresting member to arrest movement of said slider toward said inner end. 5. The specimen holder support device of  claim 4 , wherein said slider-arresting member consists of a lever having first and second ends and held so as to be rotatable about the axis of rotation of the arresting member adjacent to the outer surface of said swinging member, said slider-arresting portion being formed at said first end, said spring being connected to said second end. claim 4 6. The specimen holder support device of  claim 5 , wherein there is further provided a linear gauge for measuring the amount of rotation of said lever. claim 5 7. A specimen holder support device for use with an electron microscope having a wall defining a vacuum tight specimen chamber, said specimen holder support device comprising: a cylindrical support member extending through said wall in an x direction and mounted to said wall;  a spherical bearing surface formed on an inner surface of said support member;  a generally cylindrical swinging member having a cylindrical bearing on an outer surface inserted in said support member and swingable about said spherical bearing in Y and Z directions perpendicular to each other and the X direction;  a specimen holder slidably mounted in said swinging member via an O-ring and having a front end extending inwardly beyond said spherical bearing surfaces;  an X-motion drive mechanism for moving said specimen holder; and  a specimen holder movement-arresting means spring biasing said specimen holder relative to said swinging member for alleviating force applied to said X-motion drive mechanism from said specimen holder when a vacuum is pulled on said chamber.