The present invention provides a safety needle and a placebo needle to be used for double blind test in which both the practitioner and the subject can be blinded. The placebo needle comprises the guide tube 13 the first stuffing 14 which is plugged into the guide tube 13 to be fixed there, to give resistance to the needle body 11 during its passage therethrough the second stuffing 17 which is plugged into the guide tube 13 to be fixed at a lower position, to give resistance to the needle body 11 during its passage through the cavity of the guide tube 13 to reach a specified depth the needle body 11 which is movably held by the first stuffing 14, and which has length sufficiently long to allow its point to stop just on/above the skin surface when the needle body 11 is advanced through the cavity of the guide tube 13 as far as possible and a stopper which is mounted to the lower end of the needle handle 12 attached to the top end of the needle body 11, or to the top end of the guide tube 13, and which prevents the needle handle 12 from advancing further into the cavity of the guide tube 13 when the needle body 11 being advanced through the cavity of the guide tube 13 reaches a point just on/above the skin surface. The safety needle corresponds to the thing which removed the second stuffing from the placebo needle. Length of the needle body of the safety needle should be in the length to reach insertion depth.
