Abstract: A low-noise fan-filter unit for providing filtered airflow is disclosed. The fan-filter unit includes a housing having at least an air inlet and a coaxial air outlet; a centrifugal fan installed in the housing for drawing air into the housing and propelling it out of the air outlet; a filter installed between the fan and the air outlet for removing impurities from the air; and a noise reduction arrangement installed between the fan and the filter for reducing noise. The noise reduction arrangements includes three parting plates incorporating with the housing to form a tortuous air passageway which U-turns the airflow at least two times. The tortuous and extended air passageway, and some sound-absorbing materials furnished along the air passageway increase the contact area between the airflow and the sound-absorbing materials, and enhance the effect of noise absorption.