A strip structure for measuring potassium ions, the strip structure comprising: a strip having an inner space for receiving a solution therein and being formed in a plate shape; an inlet formed in the strip and capable of injecting a solution into the inner space of the strip ; a potassium ion selective membrane arranged in the inner space and capable of permeating potassium ions of the solution; and a first working electrode extending in a strip shape, wherein one side of the first working electrode is arranged inside the potassium ion selective membrane and the other side of the first working electrode is on a surface of the strip , the inside of the potassium ion selective membrane referring to an area where the solution would be permeated through the potassium ion selective membrane ; wherein the strip structure further comprises: a blood filter membrane arranged in the inner space and capable of removing foreign matter of the solution, and the blood filter membrane is arranged between the inlet and the potassium ion selective membrane ; and a measuring device comprising a reference electrode and an inlet into which the strip is insertable, the strip comprising an insertion hole arranged in the surface of the strip and communicating with the inner space , and the reference electrode of the measuring device being configured to be insertable into the insertion hole when the strip is inserted into the measuring device ; and wherein the measuring device is separated from the strip and is configured to measure potassium ions when the strip is inserted into the inlet of the measuring device . a strip having an inner space for receiving a solution therein and being formed in a plate shape; an inlet formed in the strip and capable of injecting a solution into the inner space of the strip ; a potassium ion selective membrane arranged in the inner space and capable of permeating potassium ions of the solution; and a first working electrode extending in a strip shape, wherein one side of the first working electrode is arranged inside the potassium ion selective membrane and the other side of the first working electrode is on a surface of the strip , the inside of the potassium ion selective membrane referring to an area where the solution would be permeated through the potassium ion selective membrane ; wherein the strip structure further comprises: a blood filter membrane arranged in the inner space and capable of removing foreign matter of the solution, and the blood filter membrane is arranged between the inlet and the potassium ion selective membrane ; and a measuring device comprising a reference electrode and an inlet into which the strip is insertable, the strip comprising an insertion hole arranged in the surface of the strip and communicating with the inner space , and the reference electrode of the measuring device being configured to be insertable into the insertion hole when the strip is inserted into the measuring device ; and wherein the measuring device is separated from the strip and is configured to measure potassium ions when the strip is inserted into the inlet of the measuring device . a blood filter membrane arranged in the inner space and capable of removing foreign matter of the solution, and the blood filter membrane is arranged between the inlet and the potassium ion selective membrane ; and a measuring device comprising a reference electrode and an inlet into which the strip is insertable, the strip comprising an insertion hole arranged in the surface of the strip and communicating with the inner space , and the reference electrode of the measuring device being configured to be insertable into the insertion hole when the strip is inserted into the measuring device ; and wherein the measuring device is separated from the strip and is configured to measure potassium ions when the strip is inserted into the inlet of the measuring device . <EOS>