There is provided a biosensor capable of increasing a detecting sensitivity of a target substance of glutamate, by using a nano wire having excellent electrical characteristics and by immobilizing a receptor of glutamate to be detected on a substrate which is disposed between a nano wire and another nano wire and a method for manufacturing the same. The biosensor for detecting glutamate according to the present invention can be manufactured with an arrangement in which the nano wire is selectively arranged on a solid substrate in a matrix. Since this biosensor can prevent the degradation of the nano wire in the electrical characteristic, it can sensitively detect glutamate even through a small amount thereof is contained in a food so that it can be effectively used in detecting the food additive existing in the processed foodstuffs.