1. A component mounting device comprising:a nozzle holder configured to turn around an axis;
a plurality of suction nozzles configured to suck an electronic component, the suction nozzles being disposed along a circumference concentric with a center of rotation of the nozzle holder and at an interval of an arrangement pitch in a circumference direction;
a horizontal over configured to allow the nozzle holder to move on a plane such that the suction nozzle at a work position set on the circumference in advance moves between a position for sucking an electronic component and a position for mounting a sucked electronic component;
a turning mechanism configured to allow the nozzle holder to be turnable along the circumference such that each of the suction nozzles alternatively moves to the work position;
an up-down mechanism configured to allow the suction nozzle at the work position to go up and down;
a camera configured to capture an image of a side portion of the suction nozzle ascending while sucking an electronic component;
a parameter storage configured to store a parameter for use in control of the camera, the parameter including at least descent start timing when each of the suction nozzles starts descent during mounting of the electronic component, and data required for determining an imaging time necessary from when the camera starts imaging of the suction nozzle until the camera ends the imaging; and
an imaging controller configured to determine imaging start timing of the camera based on the parameter stored in the parameter storage such that imaging is completed after one suction nozzle ascending while sucking an electronic component to be mounted turns from one arrangement pitch ahead of the work position toward the work position and immediately before the suction nozzle starts descent at the work position.