To prevent variation of an internal pressure of a boot even if the boot is deformed and its internal volume is varied in fitting the boot to a shaft member and a joint.

The boot 35 attached to an inboard joint 3 mounted on an intermediate shaft 2 of a drive shaft 1 and closing an opening is made into the following constitution. Lips 37a, 37b, 37c projected to an inner side in a radial direction are provided on an inner peripheral side of a large diameter end 35c of the boot 35. In the first lip 37b at a center in the axial direction, a projection amount L1 to an inner side in the radial direction is large and notch parts 38 are provided at a plurality of portions in a circumferential direction. In the second lips 37a, 37c at both ends in the axial direction, projection amounts La, Lc to the inner side in the radial direction are smaller than the L1 and a notch part is not provided.