The gold standard for diagnosis of obstructive sleep apnea (OSA) is the sleep laboratory polysomnography, which is technically demanding, labor-intensive, and time-consuming. Thus, screening of large undiagnosed population for OSA may be cost efficient only by means of ambulatory devices suitable for home recordings. The aim of our study was to evaluate the diagnostic and technical reliability of a novel ambulatory device (APV2, Remote Analysis Oy) introduced for sleep apnea diagnostics. APV2 records breathing movements, nasal and oral air flow, position, snore, blood oxygen saturation, and heart rate. The evaluation was done by comparing 10 simultaneous polygraphic recordings with APV2 and with commonly used clinical reference instrumentation (Embla, Embla Co.) at a sleep laboratory. Furthermore, the technical reliability of measurements was evaluated by analyzing the fraction of clinical APV2 and Embletta (Embla Co.) home recordings (n = 149 and n = 169, respectively) that were technically of diagnostically unacceptable quality. Similar diagnostic sensitivity in detecting OSA was found with the APV2 compared to the simultaneous reference recording with the Embla. Apnea-hypopnea indices and oxygen desaturation indices, recorded with APV2 and Embla, were closely correlated (r = 0.996-0.997, p < 0.0001). The quality of 90.0% of home recordings with APV2 was technically perfect and 96.0% of recordings were of diagnostically acceptable quality. As a comparison, the clinical evaluation of a widely used ambulatory polygraphy device (Embletta) showed that 77.2% of home recordings were technically perfect and 80.8% of recordings were diagnostically acceptable. In conclusion, the novel device was found clinically applicable, technically reliable, and sensitive for the diagnostics of OSA.