A continuously variable transmission includes a cylinder member fixed to the fix pulley, and including a cylinder cylindrical portion radially inside a pulley cylindrical portion of the slide pulley, the cylinder cylindrical portion including a groove which is formed on an outer circumference of the cylinder cylindrical portion, and which extends in an axial direction, the groove including a first groove portion which functions as a sensed portion of the rotation speed sensor, and a second groove portion which is other than the first groove portion, and wherein the continuously variable transmission includes a plunger located radially inside the pulley cylindrical portion; the cylinder cylindrical portion includes an abutment portion abutted on the plunger; and the thickness decreasing portion is not formed in the abutment portion.