The brittle fracture surfaces of Ti3Al+Nb and Ti3Al were investigated with a scanning tunneling microscope (STM) under ambient conditions using a mechanically cut platinum iridium alloy wire and electrochemically etched tungsten tips. The results show that the fracture surfaces consist of cleavage steps with dimensions of the order of approximately 2 nm for Ti3Al+Nb and approximately 60 nm for Ti3Al, similar to cleavage surfaces observed by scanning electron microscopy. Some cavities between the microcleavage steps on the scale of a few nanometers were observed for Ti3Al+Nb. The reproducibility of the STM images under ambient conditions depends on the applied bias voltage. The quality of the STM images obtained via tungsten tips is better.