Abstract: A velocity sensor for detecting velocity even in a low velocity range has a velocity detecting element including a movable micromember, a deviation amount detecting device, a holding device and a velocity signal calculating device. The movable micromember is rotatably supported around a center of gravity for generating a frictional force or a dynamical pressure that is proportional to a velocity of a fluid. The deviation amount detecting device detects a deviation amount around the center of gravity of the movable micromember to generate an output voltage, which is proportional to the detected deviation amount. The holding device provides a holding force, which is proportional to the output voltage of the deviation amount detecting device, to the movable micromember and holds the movable micromember to a position around the center of gravity. The velocity signal calculating device calculates a velocity signal from the output of the deviation amount detecting device.