To provide an agitator truck capable of transporting a large amount of concrete at low fuel consumption within a range decided by law.

A drum (1) mounted to a vehicle (A) is constituted by connecting an end plate (2) located in a front receiving member side, a front shell (3), a center shell (4), and a rear shell (5) located in a rear receiving member side by welding so as to exhibit a substantial drum shape as a whole to one another. The front shell (3) and the center shell (4) are formed of steel plates thinner than the end plate (2) and thinner than the rear shell (5). The center shell (4) is constituted of a plurality of shells according to the need.