A belt sander comprising a sanding belt, a sanding belt housing accommodating the sanding belt, a motor, a motor housing accommodating the motor, a handle, an active wheel, a driven wheel, and a transmission device connecting said motor to the active wheel, the motor housing and the handle being integrally connected to form a unitary body, and a connecting device connecting the unitary body to the sanding belt housing, said unitary body being able to rotate about its rotational axis, which facilitates the belt sander being situated in a comfortable operating position, and which can reduce the operators fatigue from working for a long time.