The invention relates to a device for preparing a beverage, comprising: - a water reservoir (1); - a chamber (5) that is connected to said reservoir for delivering water; - means (17) for filling said chamber with water; - means (16) for emptying water from the chamber; - a compressed gas reservoir (2) with a three-way valve (4) for displacing said means so as to empty the chamber; and - a conduit (14) for conveying the water from the chamber to an extraction head.
