Abstract: In order to provide a pressure equalization apparatus (10) by means of which a pressure equalization can be brought about in the event of an overpressure—in particular, in an electrochemical system—and which is as simple as possible to produce, according to the invention, the pressure equalization apparatus comprises a main element (110), a sealing device (112), and a connection device (114) for connecting the main element and the sealing device, wherein the sealing device sealingly bears against the main element when the pressure equalization apparatus is in a closed state and is fixed relative to the main element by means of the connection device, and wherein a fixing connection between the main element and the sealing device which is formed thereby can be released in order to unblock a fluid connection between the interior of the pressure equalization apparatus and surroundings of the pressure equalization apparatus, and wherein the connection device comprises a spring element (150), the spring force of wh