We investigated the transport of heavy ion induced electrons in solids by both numerical simulations and measurement: Electron yields and double differential spectra of electrons have been studied as a function of target thickness d. We measured electron yields from the beam entrance and exit surfaces of thin carbon foils bombarded with swift highly charged heavy ions at 13.6 MeV/u (Ar, foil thickness d 4 μg/cm 2 -360 μg/cm 2 ) and 74 MeV/u (Ni, d 3 μg/cm 2 -50 mg/cm 2 ) and compared the results to numerical simulations. Also, double differential (in velocity and angle) spectra of electrons emitted into the forward direction from C foils induced by Ar 1 7 + at 13.6 MeV/u reveal the dependence of the shape of the @'binary encounter@' electron peak on thickness d.