To provide a stirrer and an auto-analyzer capable of restraining a sample liquid from becoming thermally affected, by moving heat generated in a piezoelectric substrate or a container of an sound wave generation means caused by the interference of sound waves, to a position located at a distant from the container.

This stirrer/auto-analyzer stirs the liquid held in the container by sound waves. The stirrer 20 is provided with a surface acoustic wave element 23, having the piezoelectric substrate 23b provided in the container 5 and an electrode 23b formed in the piezoelectric substrate, and for generating the sound waves for stirring the liquid, and a heat-conducting member 24 provided on the container or a discontinuous face 23e of an acoustic impedance of the piezoelectric substrate; and for making the heat generated by the interference of the sound waves emitted from the surface acoustic wave element with the sound waves reflected on the discontinuous face, move to a position at distant from the container.