The present invention provides an air lift apparatus having an air supply device in a coil spring shape, capable of easily supplying air up to the bottom surface of a fish farm by applying a relatively smaller air pressure. According to one embodiment of the present invention, the air supply apparatus comprises: a cylindrical core member placed at the center and made of a metallic material a sheath member placed close to the outer circumference of the core member to water-tightly surround the core member and an air dispersion member placed by being spaced apart from the sheath member in a predetermined distance to form an air supply path (S) between an outer circumferential surface of the sheath member and an inner circumferential surface of the air dispersion member. Therefore, the air supply device can have a coil spring shape formed by winding a shape of the core member in the coil spring shape.COPYRIGHT KIPO 2016본 실시예에 따른 공기 공급기는 중앙에 배치되며, 금속 재질로 형성되는 원기둥 형상의 코어부재 상기 코어부재의 외주면에 밀착 배치되어, 상기 코어부재를 수밀(水密)하게 감싸는 피복부재 및 상기 피복부재와 일정 간격 이격 배치되어, 내주면과 피복부재의 외주면 사이에 공기 공급유로(S)를 형성하는 공기 분산부재를 포함하며, 상기 코어부재의 형상을 코일 스프링 형태로 말아서 형성하는 코일 스프링 형태를 가질 수 있다.
