To improve the characteristics in various circuits by arranging electrodes in the transmission direction of a surface acoustic wave in prescribed intervals and providing a reflector having an interrupt part, where the array of the electrodes is interrupted.

A reflector 30 is constituted of a first reflection part 31 in which 400 electrodes 34 are arranged in the transmitting direction of the surface acoustic wave at the prescribed intervals, a second reflection part 32 where 400 electrodes 34 are arranged in the transmission direction at the prescribed intervals and the interrupt part 33 having the gap of 200 μm equivalent to the interval, where 400 electrodes 34 are arranged in a position sandwiched by the two reflection parts. The reflector 30 having the interrupt part 33 is provided in a position sandwiched by a transmitter 10 and a receiver 20. Thus, a region where a reflectance attenuates appears only in a narrow band which is a part of the stop band of the reflector 30. Namely, the surface acoustic wave passes through the reflector 30 from the transmitter 10 to the receiver 20 in this region.