To provide an insulating member for a saddle-furnished snap tap capable of being set certainly on a saddle and a band and assuring excellent easiness to handle.

A saddle-furnished snap tap includes a saddle 50 to be fixed to the periphery of a service water main pipe, a band 55 installed in such a manner as confronting with the main pipe interposed and fixed to the periphery of the main pipe, and a bolt 61 and nut 65 to couple together the saddle 50 and band 55, and this snap tap is arranged so as to be secured to the main pipe by fastening the bolt 61 and the nut 65 with insulating member 1 interposed, wherein the insulating members 1 and 1' are composed of insulation bodies 10 and 20 made of synthetic resin furnished with a plurality of circumferential grooves 12 and 22 and a stopper ring 30 furnished internally with a pawl 33 which can be engaged with the circumferential grooves 12 and 22 when it makes elastic deformation. The saddle 50 and band 55 have mounting holes in which the insulation bodies 10 and 20 are fitted loosely, and the pawl 33 is engaged with the grooves 12 and 22 by intruding the stopper ring 30 into the insulation bodies 10 and 20 from the opposite sides so that the two are consolidated.