To solve the problem of a conventional mixer having a rotary vessel that since rotation and rocking of the vessel are held and transmitted by a roller, strength of the vessel and finishing of a contact face are required, therefore, an exclusive vessel is used, and attachment and detachment are not easy.

In the mixer having the rotary vessel, the vessel is fixed to a rotary and rocking vessel holder. This mechanism allows to use an inexpensive commercial plastic drum, a stainless drum or a steel drum as a mixing vessel, facilitating detaching.