A sampling device for sampling body fluid includes a casing which is pressed against a skin surface to produce a seal therewith. A cocking mechanism is pulled rearwardly to place a lancing device in a cocked state. By releasing a trigger, the lancing device is driven forward to produce an incision in the skin, and then is retracted out of the incision. A plunger mounted on the cocking mechanism is then retracted to generate a negative pressure at the front end of the casing to draw body fluid from the incision.