PURPOSE: To provide a needle selector which is capable of selecting the position of the needle.

CONSTITUTION: The needle selector 1 of a circular knitting machine is disposed on the same plane as the needle and is provided with a vibrating arm 7 having a head which is abutted to the lower part of a sub-needle. The arm 7 has two heels 8, 10, different in level, which are engaged with a countour part of an ascending cam at the bottom thereof. The arm 7 is set to selectively move to the side postion where the heels 8, 10, different in level, do not interfere with the contour part of the ascending cam or to two positions where one of the two heels 8, 10 interferes with the contour part 9. The low position, the casting position and the above holding position of the needle 2 are obtained in these positions of the arm 7, respectively.