A component mounting device includes a component supply device that supplies a component to a component supply position by using a component housing tape, a head unit provided with a suction nozzle that can be moved up and down, a first image capturing unit that captures the component supplied to the component supply position, and a component posture determination unit that determines the posture of the component supplied to the component supply position. Based on a captured image captured by the first image capturing unit, the component posture determination unit determines whether the component takes an abnormal posture protruding from a component housing part in a direction intersecting the vertical direction on a horizontal plane in the component housing tape.