To provide a propeller which reduces the complexity of propeller blade production as well as reduces the danger of maladjustment of the blades and which, despite these reductions, is capable of providing all possible desired pitches.

This propeller is provided with a hub 1 in which at least one seat 2 is formed therein, a propeller blade having a base 7 which is able to be accommodated in the seat and which has a notch formed therein, at least one key 11 which is able to be accommodated in the notch and which has a bore formed therein, and a pin 13 engageable with the bore for positioning the propeller blade with respect to the seat in an angular position corresponding to the pitch determined by the key 11.