A large number of devices similar to the laryngeal mask airway (LMA) have been developed for anesthesiologists. The ProSeal LMA (PLMA) has now become one of the standard tools for maintenance of the airway during general anesthesia. However, the LMA family requires training to be used skillfully. Lectures have therefore been created to facilitate placement of PLMA. From the viewpoint of a recent trend, our clinical studies, intended to be useful in clinical situations, were introduced.