PURPOSE: To constitute a delaying circuit and a comb type filter circuit, by using a two-terminal type ultrasonic wave delaying line having common input and output termials, through the constitution that a signal difference through two signal paths is outputted from a resistance type differential bridge.

CONSTITUTION: A signal given to an input terminal 13 is branched into two; one passes through a variable resistor 15 and is inputted to a terminal A opposing to a ground terminal D of a resistance type differential bridge consisting of resistor 19∼22, and another passes through a two-terminal type ultrasonic wave delaying line 17 having common input and output terminals and a matching circuit 16 and is inputted to a unbalancing-balancing converter 18 where the signal is converted into a balanced signal, and is inputted to terminals B and C of the resistance differential bridge. With a suitable value of the resistors 19∼22, a difference of voltage applied between the terminals A and D, and B and C can be picked up from the terminals C and D. This circuit can be used as a delay circuit using the delaying line 17 or a comb type filter, by adjusting the resistor 15.