To simultaneously (approximately simultaneously) drive a plurality of operation mechanisms and separately use fluid to which any component is added and fluid to which no component is added by providing a plurality of fluid passages.

In this fluid supply mechanism in a joint part, the plurality of fluid passages 2a, 2b are formed by dividing an inner part of a joint portion for supplying fluid from a fluid supply source to the operation mechanisms a, b of an appropriate machine into a plurality of sections. Fluid from the fluid supply source is supplied from the respective fluid passages 2a, 2b to the operation mechanisms a, b different from each other.