The invention relates to a device for extracting elements from a cavity, preferably for use in assistance during deliveries and the extraction of elements housed in cavities in the human body. The invention is formed by a bag having two ends, one of which is open and through which the element to be extracted can be inserted. In a first embodiment, the outer surface of the bag and all of the circumference thereof is provided with at least one air chamber capable of coming into contact with the element to be extracted in response to internal pressure, said chamber being connected to a pressure-generating means. In a second embodiment, the bag is provided with an outward fold, forming an annular cavity upon contact with the cavity containing the element to be extracted.