Provided are an injection head, and a substrate treatment apparatus and method using the same. The substrate treatment apparatus includes a rotatable spin head supporting a substrate, an injection head installed on the spin head to supply a fluid to a bottom surface of the substrate supported on the spin head, and a fluid supply unit supplying the fluid to the injection head. The injection head includes a body disposed below a center region of the substrate supported on the spin head to receive the fluid from the fluid supply unit and a injection member extending from the body to an edge region of the substrate supported on the spin head to inject the fluid supplied from the body to the bottom surface of the substrate, the injection member having first injection openings injecting the fluid to the edge region of the substrate and second injection openings injecting the fluid to a middle region disposed between the center region and the edge region, and a flow path through which the fluid is supplied to the first injection openings and then to the second injection openings.