Patent ID: 8399263

Claim:
An expansion/contraction measuring method comprising: transporting an expandable/contractible substrate along a surface of the substrate; detecting first and second marks which are formed on the substrate while being separated from each other by a predetermined spacing distance in a transport direction of the substrate and which are moved, in accordance with the transport of the substrate, to first and second detection areas disposed on a transport route for the substrate respectively; setting a length of the substrate along the transport route between the first and second detection areas to a reference length; and deriving information about expansion/contraction of the substrate in relation to the transport direction based on a detection result of the first and second marks, wherein the substrate is transported while being hung on a support member and folded back; the first detection area and the second detection area are arranged opposite to each other, the first detection area being disposed on an upstream side in the transport direction from a folding portion, of the substrate, at which the substrate is folded back by the support member, the second detection area being disposed on a downstream side of the folding portion.