A puncturing needle assisting tool. A first rotating portion 122 rotates from an open to a closed position, around a first hinge connecting portion 126 as the rotating center, to the surface side of an assisting tool main unit 112 to close the surface opening of a first guide groove 116a. A second rotating portion 124 rotates from an open position to a closed position, around a second hinge connecting portion 128 as the rotating center, to the surface side of an assisting tool main unit 112 to close the surface openings of second guide grooves 116b through 116d. The puncturing needles move along the guide grooves to puncture into the body in a proper state, without shifting. Locking protrusions 134, 130 maintain the closed positions of the first and second rotating portions 122, 124 respectively.
