NOVELTY - A printed circuit board (1) comprises an insulating layer (2) having two regions; two conductor portions respectively formed on two regions of insulating layer; two extraction portions (5a, 5b), each being integrally formed with conductor portion; and two coating layers (6, 7a). The insulating layer can be bent at bend portion between two regions such that the two regions are opposite to each other. Each of the first coating layer and the second coating portion of the second coating layer are made of resin composition containing carbon.    USE - A printed circuit board used in fuel cell (30) (claimed).    ADVANTAGE - The first coating layer and the second coating portion of the second coating layer suppress the increase in the thickness of the printed circuit board, and reliably prevent the corrosion of the conductor portions and extraction portions of a fuel cell utilizing the printed circuit board, even in a state where acid of methanol supplied as fuel is in contact with the printed circuit board. The first coating portion of the second coating layer is thinner than the second coating portion of the second coating layer, thus flexibility of the first coating portion is ensured and the second extraction portion above the bend portion can be reliably protected.    DETAILED DESCRIPTION - A printed circuit board (1) comprises an insulating layer (2) having two regions, where one region has three regions; two conductor portions respectively formed on two regions of insulating layer; two extraction portions (5a, 5b), each being integrally formed with conductor portion; and two coating layers (6, 7a). One extraction portion extends from first region to the third region of the insulating layer, and the other extraction portion extends from second portion to third region through first region of insulating layer. Each coating layer covers one conductor portion and one extraction portion on the insulating layer. The insulating layer can be bent at bend portion between two regions such that the two regions are opposite to each other. The second coating layer includes first coating portion that covers a portion, above the bend portion of the insulating layer, of the second extraction portion; and second coating portion formed on a region of insulating layer excluding the bend portion. Each of the first coating layer and the second coating portion of the second coating layer are made of resin composition containing carbon. The first coating portion of the second coating layer has higher flexibility than the second coating portion of the second coating layer. The first coating portion of the second coating layer has a thickness of 5-20 mu m. Each of the first coating layer and the second coating portion has a thickness of 5-30 mu m.    DESCRIPTION OF DRAWING(S) - The drawings show the diagram of the configuration of fuel cell using the flexible printed circuit board.    Printed circuit board (1)    Insulating layer (2)    Extraction portions (5a, 5b)    Coating layers (6, 7a)    Fuel cell (30)