Provided is a decompression device 50 by which varied stimulus and tightening force to a penis by an appropriate pressure can be obtained by adjusting increase/decrease in a pressure in a container 2 as a pressure source that causes the stimulus and the tightening force. There is provided the decompression device 50 being mounted to the ejaculation promotion device 1 including an ejaculation promotion apparatus 10 and a container 2, and being configured to decompress the container 2, the ejaculation promotion apparatus 10 being made of a gel-like resin and including an insertion empty space 15 and a valve section 10a that enables communication between an inside and an outside of the insertion empty space 15, the container 2 accommodating the ejaculation promotion apparatus 10, and the decompression device 50 includes: a negative pressure introducing section 55 that communicates with an air vent hole 3b provided in the container a negative pressure generating section 53 that generates a negative pressure to be introduced into the container 2 through the negative pressure introducing section 55 and the air vent hole 33 and a negative pressure adjusting section 60 that adjusts the negative pressure supplied to the container 2 through the negative pressure introducing section 55.
