There is provided a microdevice which supplies two or more kinds of fluids flowed into itself independently toward a joining region respectively, and which discharges those fluids from the joining region. The microdevice is constituted by a supply channel which supplies each fluid flowed into the microdevice toward the joining region and a discharge channel which discharges the joined fluid from the joining region toward outside of the microdevice, in a manner that a supply channel which supplies at least one kind of the fluid has a plurality of subchannels which supply the fluid supplied into the microdevice toward the joining region, and those subchannels and supply channels are formed so that at least one central axis of the plurality of subchannels and at least one central axis of the supply channel which supplies at least one kind of fluid other than the kind that the subchannel supplies or of the subchannel intersect at one point.