An apparatus is disclosed for treating a user by means of vibrations, comprising: a vessel for accommodating a liquid for immersing the user, provided with a first rim; a motor provided with a cam mechanically coupled to the vessel to cause vibrations of the vessel. The apparatus is characterized in that it further comprises an external casing of the vessel, provided with a second rim covering the first rim, and a fluid-tight seal interposes between the first rim and the second rim and such to reduce the transmission of vibrations from the vessel to the casing.