Gastroesophageal reflux disease (GERD) considered to be associated with mucosal damages in the esophagus and heartburn, which may sometimes interfere with daily activities due likely to reflux of acid gastric contents. While most of the patients given the diagnosis of GERD do not exhibit endoscopically obvious impairment in esophageal mucous membrane, they have subjective symptoms of non-erosive GERD including heartburn. But no drug has been launched in Japan, which targets non-erosive GERD. This study will examine the efficacy and safety of famotidine in subjects with non-erosive GERD.