This specification discloses a fastening band surrounding a cylindrical fastening member mounted on a member to be fastened and having the opposite end portions thereof adapted to be superposed one upon the other when the fastening member is fastened to the member to be fastened. A rectangular hole and slot extending long in the lengthwise direction of the body of the band are formed in succession from the fore end in a first end portion which is the outer side when the opposite end portions are superposed one upon the other. The end edge of the rectangular hole which is adjacent to the fore end provides a first tool engaging portion. A first projection for tentative fastening and regular fastening is inwardly formed on the end edge of the slot which is adjacent to the fore end. A second tool engaging portion comprising a protuberance, a second projection for tentative fastening and a third projection for regular fastening are outwardly formed in succession from the fore end on a second end portion which is the inner side when the opposite end portions are superposed one upon the other. By applying a force in the tangential direction of the fastening band in its tentatively fastened state to the first tool engaging portion, the first projection is caused to ride over the third projection and thereafter is caused to engage the third projection to thereby bring about a regularly fastened state.