<p>A cartridge (A) is loaded on a separate device and is provided with a liquid introducing inlet (3) for introducing a sample liquid; and a diluting means (4) which includes a diluting solution tank (41) wherein a diluting solution (40) for diluting the sample liquid is stored, a sample liquid measuring means (43) for separating a prescribed quantity from the sample liquid introduced from the liquid introducing inlet (3), and a diluting tank (42A) for mixing at least a part of the sample liquid with a part of the diluting solution. The sample liquid measuring means (4) includes an introducing flow path (43a) extending from the liquid introducing inlet (3), a measuring flow path (43c) and an overflow path (43d) connected to the introducing flow path (43a) through a branch section (43b), and the measuring flow path (43c) extends to the diluting tank (42A).</p>
