A valve device includes a main body case to which an inflow pipe and an
outflow pipe are connected, a valve element which is disposed inside of
the main body case to open or close an outflow aperture part of the main
body case, a motor for moving the valve element in an open direction and
a closed direction, a valve element drive means which is driven by the
motor and includes a rotary member rotated by the motor and a rotation
side permanent magnet mounted in the rotary member, a valve element side
permanent magnet mounted in the valve element, and a holding member which
movably holds the valve element. The valve element is urged in the open
direction or the closed direction by a magnetic attractive force or a
magnetic repulsive force generated between the rotation side permanent
magnet and the valve element side permanent magnet.