PURPOSE: To provide the titled device capable of defoaming and recovering highly viscous liquid contg. foams in performing defoaming operation using a rotary rotor by separately discharging foam-contg. liquid separated to foams and liquid in the neighbourhood of a separating wall at the bottom of a downwardly expanded rotor through each penetrating hole.

CONSTITUTION: The liquid 10 is collected centrifugally to the bottom of a downwardly expanded rotary rotor 1 in a casing 5 and to the neighbourhood of a separating wall 2 at the bottom of the rotor, and contained foams 11 are floated up. The liquid is then discharged from a discharging hole 4 for the defoamed liquid at the bottom of the periphery of the separating wall 2, and recovered from a discharge port 7 for the defoamed liquid at the bottom wall 5b of the casing. Floated foams flow through a discharge hole 3 from the inside edge of the separating wall 2 and is discharged through a discharge port 8 for foams of the casing 5. The defoamed highly viscous liquid is recovered with satisfactory condition without causing reentanglement of foams.