This paper presents the validation of a noninvasive sleep monitoring device and sleep quality evaluation. The system is based on an array of pressure sensors positioned on the bed that can measure relevant parameters to estimate sleep quality. This device can measure time in bed (TB), body movements (BM), the thorax expansion, periods out of bed (POB) and apnea events. We compare the results of the unobtrusive pressure sensor array with traditional polysomnography (PSG). The algorithms developed for the device provide a very good detection of all the parameters required to estimate sleep quality as compared to the gold-standard data for a study of 30 patients. For the periods out of bed it presents a sensibility (Se) and specificity (Sp) of 100%. To grade the severity of sleep apnea we compare the number of events per hour or apnea-hypopnea index (AHI) obtained by the device and the PSG; obtaining a Se of 94% and a Sp of 61%. These results validate the use of the device for screening of sleep apnea disease.