A quantitative flour feeding unit of a noodle making machine which can easily be exchanged with another one for making a different kind of noodle using a different kind of flour including a support platform on which a hopper and a rotational driving mechanism are mounted to quantitatively feeding the flour stored in the hopper to a flour kneading unit. The support platform is removably mounted on a housing of the noodle making machine by a position determining unit to enable the exchange with the position determining unit including a V-shaped groove formed at one corner of the support platform and a stationary knob disposed on the support platform at another diametrically located platform corner. The noodle making machine has a unit for transmitting the power generated by a motor to the rotational driving mechanism and a unit for setting and indicating what kind of flour is being used at present.