To surely convert reciprocating motion of a slider to oscillating motion of a rotary stirring arm even when frying refuse or other foreign matter enters.

In an apparatus for reducing volume of frying refuse such as tempura refuse and deep-fried refuse by compression and for squeeze contained oil, an oscillating arm 23 is provided projectingly in a downward direction at a rotary shaft 19 provided at the rotary stirring arm by intersecting a shaft center 19Z of the rotary shaft 19, a recessed part 24 opening downward is provided at a top end 23B side of the oscillating arm 23 and a sliding member 28 which is inserted via an opening 25 and can slide between an opening 25 side of the recessed part 24 and an deep part 27 of the recessed part 24 is provided integrally with the slider 8 to form a reciprocating motion-oscillating motion converting means 22. Even when the frying refuse or the like attaches to the recessed part 24, it drops at once since the recessed part 24 is downward and consequently reciprocating motion of the sliding member 28 can be surely transmitted to the oscillating motion of the oscillating arm 23.