To provide an agitator in which a conventional excitation arm is eliminated; the number of component items is reduced, simple constitution and reduction in manufacturing cost are realized; installation/dismounting work before and after excitation is performed easily and rapidly; unique usage is intended; and a body to be excited is sufficiently held to obtain a stable excitation state.

In an agitator capable of placing a body 22 to be excited on a placing member 20 simultaneously movable with a piston rod 10 of an excitation cylinder 8, the excitation cylinder 8 is erected on a backside a base 1 that can land on a ground part 2. An elevatable plate 15 is linked simultaneous- operatably to the piston rode 10 of the excitation cylinder 8. The placing member 20 is disposed on the lower end of the elevatable plate 15; the placing member 20 is projected forward. The body 22 to be excited is engageably accommodated in between the elevatable plate 15 and the placing member 20.