A slot curtain coating apparatus, including: ejecting unit containing coating liquid outlet to eject coating liquid; pair of guiding units, each containing auxiliary water outlet to eject auxiliary water, the guiding units being configured to support both edges of curtain film formed of the coating liquid ejected from the coating liquid outlet along width-direction substantially vertical to flow-down direction of the curtain film, and to guide the curtain film onto support transported; and transporting unit to transport the support, wherein the guiding unit has manifold portion to retain the auxiliary water, and slit portion connecting between the manifold portion and the auxiliary water outlet, the slit portion is composed of straight-line portion, and curved portion to eject the auxiliary water substantially vertically downwards, and curvature radius R of bottom part of the curved portion is 0.5 mm-3 mm, and the curved portion is provided to position at which h=T+R+S is 1.5 mm-5 mm.