Inlet valve for supplying a liquid to an interior space of a chamber system or sample container, or for introducing a sample into the interior space of a chamber system or sample container, wherein the inlet valve is designed for adding the liquid or sample by means of a tool (19, 19') and comprises a first axis, and wherein the inlet valve comprises an inlet opening and said inlet opening is formed to automatically reclose, characterized in that the inlet valve comprises: (a) a valve body arranged in the inlet opening and movable in the direction of the first axis between a closing position and an open position, comprising: - a blocking element comprising a sealing surface, - a pressure part spaced from the blocking element and loadable with a tool (19, 19'), and comprising a liquid passage in the region of the first axis, - a neck or a hollow tube which connects the blocking element and the pressure part to each other and which comprises at least one open passage region which on the one hand is designed to open into the liquid passage of the pressure part and on the other hand is designed to open into a valve chamber; (b) a valve chamber surrounding the valve body at least partially in the region of the neck or hollow tube; (c) a spring mechanism (13; 30; 40) which on the one hand is formed to engage on the pressure part or the blocking element and on the other hand is designed to engage on a wall of the chamber system or an end cap element of the sample container; and (d) a sealing element connected to an inner wall of the chamber system or to an end cap element of the sample container, wherein the spring mechanism (13; 30; 40) is adapted to press the sealing surface of the blocking element against the sealing element in the closing position of the valve body, and wherein the valve body of the inlet valve is adapted so that it can be brought into the open position by acting upon the pressure part against the resistance of the spring mechanism (13; 30; 40). (a) a valve body arranged in the inlet opening and movable in the direction of the first axis between a closing position and an open position, comprising: - a blocking element comprising a sealing surface, - a pressure part spaced from the blocking element and loadable with a tool (19, 19'), and comprising a liquid passage in the region of the first axis, - a neck or a hollow tube which connects the blocking element and the pressure part to each other and which comprises at least one open passage region which on the one hand is designed to open into the liquid passage of the pressure part and on the other hand is designed to open into a valve chamber; - a blocking element comprising a sealing surface, - a pressure part spaced from the blocking element and loadable with a tool (19, 19'), and comprising a liquid passage in the region of the first axis, - a neck or a hollow tube which connects the blocking element and the pressure part to each other and which comprises at least one open passage region which on the one hand is designed to open into the liquid passage of the pressure part and on the other hand is designed to open into a valve chamber; (b) a valve chamber surrounding the valve body at least partially in the region of the neck or hollow tube; (c) a spring mechanism (13; 30; 40) which on the one hand is formed to engage on the pressure part or the blocking element and on the other hand is designed to engage on a wall of the chamber system or an end cap element of the sample container; and (d) a sealing element connected to an inner wall of the chamber system or to an end cap element of the sample container, wherein the spring mechanism (13; 30; 40) is adapted to press the sealing surface of the blocking element against the sealing element in the closing position of the valve body, and wherein the valve body of the inlet valve is adapted so that it can be brought into the open position by acting upon the pressure part against the resistance of the spring mechanism (13; 30; 40).