Abstract: A low-temperature stage for use in an electron microscope comprises a main body (37), a holder (10) for a specimen mount, a heat exchanger (16) within the main body (37), conduit means (14, 18) for supplying coolant to the heat exchanger, a bar (22) of relatively large cross-section and relatively high thermal conductivity interconnecting the heat exchanger (16) and the specimen mount holder (10) to form a heat transfer path therebetween, and a support member (28) of relatively small cross-section and relatively low thermal conductivity interconnecting the specimen mount holder (10) and the main body (37), the support member (28) being a generally box-shaped member (28) disposed around said bar. An anti-contaminator for an electron microscope, comprising a metallic cryogenic shield (58), a tank (50) for holding a cryogenic liquid maintained at boiling point, and a thermal pathway (60) between the shield (58) and the tank (50).