The present application discloses an atrium retractor with a plate and a shaft that has a shaft sleeve, an inner rod and an operating mechanism. The operating mechanism is designed to generate a relative movement between the shaft sleeve and the inner rod. An articulation device that is firmly connected either to the plate or the shaft and is detachably connectable to the other from the plate or the shaft is provided in the atrium retractor. The operating mechanism is adapted to optionally lock and release the articulated connection by means of the relative movement between the shaft sleeve and the inner rod.
