A piezoelectric micropositioner for coarse sample translation in a scanning tunneling microscope (STM) has been designed. The mechanical construction for the positioner is very simple, and it can be separated from the sample carriage during STM imaging. The coarse sample movement is obtained via a sliding-pushing mechanism, and a displacement speed of 0.1 mm/s has been attained. The performance of the STM is tested by imaging a highly oriented pyrolytic graphite sample.