Hydrogen produces no harmful by-products upon combustion, but it is highly flammable gas over a concentration of 4%2in the air. In order to use hydrogen gas safely, therefore, the hydrogen safety sensor is required wherever using the hydrogen gas. Conventionally, Palladium (I'd) metal has long been used for the safety sensors because of its high hydrogen sensitivity and selectivity to other gases. In this study, we demonstrated the hydrogen sensing using I'd nanowire array as a proto-type sensor. Especially we focused on fabricating a proto-type hydrogen safety sensor and evaluating the sensing performance of the sensor.