The invention relates to a magnetic switch (10) for level measurement of a fluid or liquid gas in a tank, such as a fuel tank, storage tank or the like in a vehicle, comprising a housing with an internal closed cavity (24) (12), the cavity extends longitudinally within the housing (12), and the body (16) is disposed at the first end (24a) of the cavity (24), adapted to pass through the mutual magnetic force of the external movable floats (18) impacted to move within the cavity (24), and at least two contacts (20a, 20b) located at the other end (24b) of the cavity (24) are arranged to provide intimate contact with said body (16), When the float (18) moves up, the contact between the body and the contacts (20a, 20b) is maintained by the magnet connection, and when the float moves down, the contacts (20a, 20b) are disconnected from the body ( 16) contact between, wherein, due to the magnetic force between the float (18) and said body (16) is stronger than the magnetic connection between contacts (20a, 20b) and said body (16), said The body (16) is pulled down. A liquid level measuring device (30) with a plurality of magnetic switches (10) and its use are also described.