To provide a coolant supply device for a vertical hydraulic machine which simplifies piping in an upper cover, has good operability of disassembling, repairing, and assembling of a hydraulic turbine, and can largely reduce number of underground pipes.

In a coolant supply device for a vertical hydraulic machine which supplies coolant from an external water supply device 20 to a plurality of cooling devices 8 for cooling bearing lubricating oil of the vertical hydraulic machine, a main member of an upper cover 1 of the vertical hydraulic machine is provided with a water reservoir 1a that uses a part of this main member as its one wall surface and extends circumferentially, a water supply pipe 15 for supplying water from the water supply device to the water reservoir is provided between this water reservoir and the water supply device 20, and a water supply pipe 12 for supplying water from the water reservoir to the cooling device is provided between this water reservoir 1a and each cooling device 8.