The lung disease burden has increased due to some factors such as pollution, smoking, pathogenic bacteria and virus. Among them, lung cancer has become the leading cause of cancer death worldwide due to its high recurrence, metastasis formation and drug resistance. For these reasons, in vitro models that reproduce the lung environment and individualized treatment are required to improve therapies efficacy. Organs-on-chips can be a powerful technology to accomplish this goal. In this thesis work, an alveolus-on-chip, which mimics the alveolar-capillary barrier, is described. The developed microfluidic device consists of two layers separated by an electrospun polycaprolactone/gelatin (PCL/Gel) membrane, where the co-culture of lung epithelial cells (A549) and lung endothelial cells (Hulec-5a) was performed by seeding the two cell lines in the upper and bottom layer of the PCL/Gel membrane, respectively.