We have designed and developed a series of room‐temperature field ion scanning tunneling microscopes (RT FI‐STMs). The great advantages of the RT FI‐STM are (1) almost simultaneous use of both the STM mode and FIM mode is possible without wasting machine time and thermal drift; (2) inspection and manipulation of a STM tip insitu in the STM system can be performed and, thus, each tip can be used over several months, maintaining a desired atomic resolution; and (3) a well‐characterized tip ensures a very high (∼100%) success rate in STM imaging with a known resolution. Several examples are given.