A component mounting device includes a head unit including a mounting head configured to mount a component on a substrate, and an imaging unit provided on the head unit and configured to image at least one of a suction position of the component to be suctioned by the mounting head and a mounting position of the component mounted by the mounting head from a plurality of directions, such that the imaging unit is configured to capture a first image and a second image. The component mounting device is configured to expand or contract the first image captured by the imaging unit in accordance with an imaging direction of the second image, and acquire a height position of an imaged location based on the first image that has been expanded or contracted and the second image.