A fluid supply apparatus which supplies a fluid to a medical apparatus includes: a pump mechanism including a first pump capable of carrying out a intake operation of the fluid after carrying out a feeding operation of the fluid, and a second pump capable of carrying out a intake operation of the fluid during the feeding operation by the first pump and carrying out a feeding operation of the fluid during the intake operation by the first pump a flow passage which includes an elastic member and which communicates with the first pump and the second pump and supplies the fluid to the medical apparatus and a flow passage deforming unit which deforms a part of the flow passage. The flow passage deforming unit starts first deformation of the flow passage before the first pump switches from the feeding operation to the intake operation, and completes the first deformation of the flow passage and starts second deformation of the flow passage during the feeding operation by the second pump.
