A single phase, dense PdCu alloy film was prepared by one-step electroplating. The electroplated film was easily delaminated from the SUS electrode by cutting around the edge, and the single alloy film was thus collectable. The phase structure, surface morphologies, and alloy compositions were determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), and electron probe microanalysis (EPMA). The plated film before and after hydrogen permeation tests consisted of a single face-centered cubic alpha phase and an ordered body-centered cubic beta phase, respectively. The atomic ratios of Pd and Cu were 49 and 51 at%, respectively; the Pd and Cu contents were slightly higher and lower than Pd47Cu53, which shows the highest hydrogen permeability among Pd-Cu systems. The asplated film exhibited high mechanical strength, and its load force at break point and displacement were 3 and 1.7 times those of the as-rolled Pd47Cu53 films. The hydrogen permeability of the plated film with the I phase was almost the same as that of the rolled film and the values reported in literature. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.