A sanding machine has a feeding device (7), which defines a support surface (A) for at least one component (2) to be sanded and is designed to move the component (2) through at least one sanding unit (66) provided with an abrasive belt (82) wound in a ring shape around at least two pulleys (81a, 81b, 81c), one of them being movable with an oscillatory reciprocating motion around a rotation axis (80), which is transverse to a longitudinal axis (88) of its, due to the thrust of two transmission shafts (94, 96), which are eccentric relative to one another and are connected - one - to the pulley (81c) and - the other one - to a frame (67) of the sanding unit (66).