A food processor includes a base, a lower cap, a blade unit and a top cap. The top cap has a fixed tube extending from an underside thereof and a sleeve is movably mounted to the fixed tube. A board is sandwiched between the sleeve and the blade disk of the blade unit so as to move the sleeve upward which then fixed to the fixed tube by an adhesive layer such that a gap with a fixed width is defined after the board is pulled away. The food can be cut into tiny particles and juice can be squeezed via the gap.