A waterproof slide fastener and a manufacturing apparatus thereof, wherein each fastener element has a coupling head, a neck portion, a body portion, and leg portions which are continuously fused and integrated, a terminal end is projected from a gap between upper/lower half portions of the coupling head, upper/lower flanges of a slider make a sliding contact with a surface of each of upper/lower half portions of each leg portion, each half portion of the leg portion is formed in a flat plate shape with a step and thinner than each half portion of the neck portion and the body portion in a direction perpendicular to a plane in which the fastener tape lies, and extending from the body portion via a crotch portion and guiding the flanges, two or more leg portions are disposed with a predetermined interval in a sliding direction.