An electronic device including a semiconductor memory. The semiconductor memory includes a bit line; a source line; a plurality of resistive memory cells among which a selected memory cell forms a current path between the bit line and the source line; a read current supply unit configured to supply read current to the bit line in a read operation; a sense amplifier configured to generate read data in response to a voltage level of the bit line in the read operation; and a variable switch element configured to flow current from the source line to a ground terminal in the read operation, and be decreased in its resistance value as a voltage level of the source line is high.