A device to extract elements contained in a cavity, additional to patent of invention P060105329, and of preferable application to assistance at childbirth and/or extraction of elements seated in cavities of the human body, facilitating the task of medical professionals. Said device is comprised of a bag having one of its ends open, through which it is possible to introduce the element to be extracted, in which, in a first embodiment and on the outer surface of the bag and along all its circumference line, there is at least one air chamber being able to get in contact with the element to be extracted when receiving inner pressure, being said chamber connected to a pressure generating means; and in a second embodiment, an outward fold is defined on said bag, forming an annular cavity at the time it gets in contact with the cavity containing the element to be extracted.