[Problem] To provide a fluid supply apparatus capable of supplying a fluid at a stable discharge speed and capable of finely adjusting a discharge flow rate of the liquid. [Solution] In a fluid supply apparatus P1 according to the present invention, a first intake chamber 3A, a second intake chamber 3B, a vacuum chamber 4, and a contraction chamber 5 are partitioned-formed via a plunger 2 that reciprocally moves in the axial direction inside a cylinder 1, wherein the fluid supply apparatus is an apparatus that discharges a liquid medicine from a discharge port 7 by the plunger 2 moving forward by the pressure of the air sucked into the first intake chamber 3A, reducing the volume of the contraction chamber 5, wherein an intake air amount adjusting mechanism 11 based on a fluid resistance is provided in a first intake port 10A linked to the first intake chamber 3.
