We investigate the in-situ cleaved n-InAs(110) surface by means of low-temperature scanning tunneling spectroscopy and microscopy in magnetic fields up to 6 T perpendicular to the surface. The dI/dV (V)-curves exhibit characteristic oscillations in magnetic fields, which can be attributed to Landau-level splitting of the conduction band. The energy dependence of the effective electron mass is determined. Spatially resolved dI/dV-images exhibit circular symmetrical corrugations at the surface. These are ascribed to scattered electron waves at dopant atoms below the surface. From the energy dependence of their diameter, the dispersion of the InAs conduction band at the Τ -point is estimated.