The electronic conduction through a Pr0.7Ca0.3MnO3 thin film is investigated by measurements using dc and pulsed bias. Pr0.7Ca0.3MnO3 films sandwiched by electrodes exhibit two stable resistance states by means of applying voltage pulses. Both of the states show semiconducting behavior. The ratio of the two resistance states induces a colossal electro-resistance (CER) effect greater than 1000%. The CER behavior is seen in the temperature range of 300 K down to 150 K. The observed conduction characteristics exhibit the space-charge-limited-current effect, and the switching behavior can be ascribed to a carrier trapping/detrapping of the trap sites in the perovskite manganite. (c) 2005 Elsevier B.V. All rights reserved.