Provided is a microfluidic device to more easily and mechanically operate a valve for controlling a fluid flow, which comprises: a platform having a plurality of chambers; at least one flow channel which connects between the chambers; and a valve which opens or closes the flow channel, wherein the valve includes a blocking member which selectively blocks the flow channel and a pressing member installed in the blocking member to move the blocking member, and the pressing member has a structure which presses and moves the blocking member by the linear reciprocating motion in the same direction as the direction of an external force, and the valve further includes a driving unit which reversibly controls the opening and closing of the flow channel caused by the blocking member by fixing the pressing member to the position of the moved pressing member or returning to the original position.