Abstract: For sewing up a surgical opening (32), an instrument (10) is provided to be introduced thereinto. Needle holders (19), having needles (25) attached thereon, are laterally extended out of the instrument (10). By raising the instrument (10), the needles (25) are pierced through the cutaneous tissue (33) from the inside to the outside while the thread (30) passing through the needles (25) forms a loop within the patient's body. A needle catcher (26) is used for withdrawing the needles (25) out of the patient's body, the needles (25) being released from the needle holders (19). Finally, the thread loop can be tied into a knot above the surgical opening (32) outside the patient's body.