The shoulder stiffness, the muscle fatigue, etc., are easily and efficiently improved by the electromagnetic waves without the usage of the power supplies and the large treatment tools. The electromagnetic-wave treatment device 10 has an antenna acupuncture needle 13 and a fixing member 12. The antenna acupuncture needle 13 has a sharp end portion 13a having one end portion formed into a needle shape. The fixing member is fixed to the antenna acupuncture needle 13. This antenna acupuncture needle 13 is fixed so that the sharp end portion 13a of the antenna acupuncture needle 13 protrudes from the fixing member 12. And, the antenna acupuncture needle 13 functions as an antenna receiving the electromagnetic waves in a space.