A transmission circuit includes a plurality of transmission lines connected in a ring to propagate signals among a plurality of devices. There can be provided a method for manufacturing a polishing pad that can stably obtain a wafer with high flatness, etc. Furthermore, the cooling device also serves as a positioning block to fix the return member, it doesn’t increase the outer diameter of the nut. In this way, the effects of additive noise on the input signal can be reduced. The apparatus can be used to form an organic emitting layer on the substrate. The receiving circuits are connected to the conductors of the interconnection, each receiving circuit being such that the 4 channels of a source connected to a transmitting circuit in the activated state are sent to the four channels of the destinations, without noticeable echo, internal crosstalk and external crosstalk.