To provide a sonic wave generating member constituted so as to stabilize the feed of power to a vibrator to properly stirr the liquid in a reaction container, the reaction container and an analyzer.

In the sonic wave generating member, the length L2 between comb-tooth like electrodes of both ends is made shorter than the length which is twice the distance between an arrival position, where the ultrasonic wave emitted toward the other surface of a piezoelectric substrate from the central position between a plurality of the comb-tooth like electrodes is reflected from the other surface of the piezoelectric substrate, and the central position between a plurality of the comb-tooth like electrodes so that the ultrasonic wave of the highest intensity emitted from the central position between a plurality of the comb-tooth like electrodes does not again enter the comb-tooth like electrodes.