A multiplexer for a semiconductor memory device which has at least two pads for inputting data signals from the outside. The multiplexer has at least two input lines for inputting the data signals from the at least two pads, respectively, at least two control lines for inputting control signals for switching the data signals from the at least two input lines, respectively, and at least two switching circuits, each of the at least two switching circuits transferring the data signal from a corresponding one of the at least two input lines to an output line in response to the control signal from a corresponding one of the at least two control lines and having a floating node formed to be electrically isolable from the output line and the corresponding input line to prevent a loss of the data signal on the output line. According to the present invention, the multiplexer can prevent a data loss due to a disturbance and accurately transfer the data signals from the at least two pads.