PURPOSE: To control the transmission route for facilitation of test.

CONSTITUTION: N type transistors TRs 1a and 1c and P type TRs 2a and 2c are connected in parallel, and a connection point (a) of TRs 1a, 1c, 2a and 2c is used as the input terminal, and N or P type TR which is in the level to be clamped at the time of non-selection, is connected to both terminals of four TRs, and they are connected to a VDD or GND terminal. A signal terminal which controls the transmission route is connected to gate terminals of TRs 1a and 2b, and it is connected to TRs 2a and 1b through an inverter circuit 8. Therefore, the circuit is constituted of TRs whose number is 2/7 of conventional.