We have developed a prototype gaseous gamma camera with a Gas Electron Multiplier (GEM) for biomolecular analysis and medical applications. The system consists of three devices: a detector, an Ethernet hub, and a Pc. The detector consists of a GEM-chamber and integrated readout electronics. The GEM-chamber consists of three parts: the gamma-ray conversion and amplification layers consisting of GEM foils, and a readout component. To increase gamma-ray-detection efficiency, we constructed a new type of GEM foil. The gamma-ray conversion layers are plated with gold 3 mu m thick on both surfaces. In order to test the performance of the prototype camera, several measurements were performed with a phantom filled with Tc-99m(141 keV) as the radioactive source, and two-dimensional (2D) images were obtained using a pinhole collimator. The camera showed good capability to resolve objects of a few mm(2).