A design is presented for a scanning tunneling microscope (STM) capable of operation over a temperature range of approximately 80–350 K in ultrahigh vacuum. An integral inchworm‐like sample translation device avoids problems with unreliability and lock‐up by using clamping elements which have an unusually large range of motion. The entire STM, including the sample and the tip, are held isothermal. Temperature drift is less than 0.1 A˚/min. A set temperature may be maintained, within 2°, for over 10 h. Operation of the instrument is demonstrated with an image of the Si(001) surface recorded at 120 K.