PROBLEM TO BE SOLVED: To provide a signal transmission substrate which reduces jitter due to strokes between signal wires without adding a circuit that adjusts phases. SOLUTION: A first signal wire 1 includes a portion that is distributed in a first layer and a portion that is distributed in a second layer. The portions 1A, 1C distributed in the first layer and the portion 1B distributed in the second layer are connected at predetermined positions 1a, 1b. A second signal wire 2 includes the portions 2A, 2C distributed in the first layer whose total length is equal to that of the portions 1A, 1C distributed in the first layer of the first signal wire 1 and the portion 2B distributed in the second layer whose total length is equal to that of the portion 1B distributed in the second layer of the first signal wire 1. The connection positions 2a, 2b between the portions 2A, 2C distributed in the first layer and the portion 2B distributed in the second layer are different from that of the first signal wire 1. COPYRIGHT: (C)2009,JPO&INPIT