A body fluid collection device for collecting body fluid through the skin, comprising: a sheet-like substrate provided with an adhesive surface; a first collection body for collecting body fluid, provided on the adhesive surface; a first detachable sheet which is detachably adhered on the adhesive surface so as to cover the first collection body; and a second detachable sheet which is detachably adhered on the adhesive surface, wherein one end of the second detachable sheet in a predetermined direction is overlaid on the far end of the first detachable sheet in the predetermined direction, and part of the far end of the first detachable sheet is separated from the adhesive surface in a non-adhered state is disclosed.