The present invention relates to an interdental toothbrush. The interdental toothbrush of the present invention has a medicament storage space 11 in which a liquid medicament is stored, and a part of a pump device 12 for spraying a liquid medicament stored in the medicament storage space 11 is provided at an upper portion thereof. And an inclined portion 14 having a diameter gradually increasing in a downward direction is formed on an inner peripheral surface of a lower end of the interdental brush attaching / detaching groove 13, 10)； The upper part of the pump device 12 protruded above the body is inserted into the body receiving groove 21 to be coupled to the body and the side of the body receiving groove 21 A lid 20 separated from the body receiving groove 21 by a partition 22a and having a brush storage space 22 in which a brush is stored； A head portion 31 inserted into the interdental brush attachment / detachment groove 13 of the lower portion of the body 10 is formed on the upper portion of the body 10, and a brush 32 is detachably connected to the lower portion of the head portion 31, Two coupling portions 33 are formed between the head portion 31 and the brush 32 so as to be inclined to correspond to the inclination angle of the inclined portion 14 in the direction opposite to each other and to be fitted into the inclined portion 14 And an interdental brush 30 which is inserted into and detached from the interdental brush attachment / detachment groove 13 so that the positions of the head 31 and the brush 32 are reversed. According to the present invention, it is possible to store a spare toothbrush brush so that the brush can be quickly used without a separate storage container, and the tooth brush can be inverted upside down to be detachable to the body, In addition, it is possible to provide a more hygienic use and storage environment by allowing the brushes of the tooth brushes and the spare brushes, which are fastened to the body during use, to be st
