The present invention is a silver alloy having excellent reflectance and transmittance, containing silver as a main component and as a first added element group at least one of dysprosium, thulium, terbium, gadolinium, erbium, neodymium, holmium, praseodymium, samarium, lanthanum, cerium, ytterbium, europium, scandium and yttrium. Here, the first added element group is preferably dysprosium, gadolinium, erbium, praseodymium, samarium, lanthanum and yttrium, and further, it is preferable to add as a second added element group at least one of gallium, copper, palladium and indium. Further, the added element concentration total is preferably 0.01 to 20.0 atom%.