A magnetic solenoid electron transporter has been constructed to investigate conversion electrons produced in a target by the bombardment of heavy‐ion beams. It measures 32 cm in diameter, 124 cm in length, and weighs approximately 290 kg. The target is located at the center of the magnet so that the emitted electrons can be transported toward either end and their energies measured in Si(Li) counters. The energy resolution (for the 624 keV line of137Cs) and the over‐all detection efficiency (for the energy range between 500 and 1200 keV) have been determined to be 6.9±0.2 keV and 6.0±0.4% for a 110 mm2counter, and 22.0±0.9 keV and 16.0±1.1% for a 500 mm2counter. This distortion of the energy spectrum for the same energy range is less than 7%.