A lancing unit (U1) includes a lancing member (2), an auxiliary part (3) which is separate from the lancing member (2), and a supporter (1) detachably supporting these. Preferably, the lancing unit (U1) further includes a cap (29) which covers a needle (21) of the lancing member (2) and which is detachable from the lancing member (2), and the lancing member (2) is supported by the supporter (1) via the cap (29) .
