We designed and constructed an ultrahigh vacuum scanning tunneling microscope (UHV‐STM) which is available for the measurement of tunneling spectra at low temperature. The sample holder is cooled by thermal conduction to the stage that thermally connects with the refrigerator head. We cleaved Bi2Sr2CaCu2Oy(Bi2212 highTcsuperconductor) single crystals under ultrahigh vacuum conditions, and measured tunneling spectra of the Bi–O surface at 35 K. The spectra were smeared due to the fact that the STM tip was at high temperature (≳100 K).