A component mounter configured to hold a component and mount the component on a surface of a board, the component mounter comprising: a head having a nozzle configured to hold the component at a nozzle tip of the nozzle; a horizontal moving means configured to move the head in a horizontal direction with respect to the surface of the board; a vertical moving means configured to move the nozzle in a vertical direction with respect to the surface of the board; a mounting control means configured to perform mounting operation of mounting the component held by the nozzle at a mounting location on the surface of the board by moving the head using the horizontal moving means such that the nozzle is positioned above the mounting position on the surface of the board and lowering the nozzle using the vertical moving means; and an imaging means provided with an optical system, the imaging means provided on the head and configured to image an imaging target by receiving incident light from the imaging target on an imaging element via the optical system, wherein the optical system includes a first optical system (88a, 88b, 88c, 88e, 88f) configured to guide incident light from a direction of a side surface of the nozzle tip to a first region of the imaging element, characterized in that the optical system includes a second optical system (88d, 88e, 88f) configured to guide incident light from a direction of the surface of the board to a second region of the imaging element in a state with the nozzle above the surface of the board, and the imaging means is configured to be able to image an image of the side surface of the nozzle tip and an image of the surface of the board respectively via the first optical system (88a, 88b, 88c, 88e, 88f) and the second optical system (88d, 88e, 88f). a head having a nozzle configured to hold the component at a nozzle tip of the nozzle; a horizontal moving means configured to move the head in a horizontal direction with respect to the surface of the board; a vertical moving means configured to move the nozzle in a vertical direction with respect to the surface of the board; a mounting control means configured to perform mounting operation of mounting the component held by the nozzle at a mounting location on the surface of the board by moving the head using the horizontal moving means such that the nozzle is positioned above the mounting position on the surface of the board and lowering the nozzle using the vertical moving means; and an imaging means provided with an optical system, the imaging means provided on the head and configured to image an imaging target by receiving incident light from the imaging target on an imaging element via the optical system, wherein the optical system includes a first optical system (88a, 88b, 88c, 88e, 88f) configured to guide incident light from a direction of a side surface of the nozzle tip to a first region of the imaging element, characterized in that the optical system includes a second optical system (88d, 88e, 88f) configured to guide incident light from a direction of the surface of the board to a second region of the imaging element in a state with the nozzle above the surface of the board, and a first optical system (88a, 88b, 88c, 88e, 88f) configured to guide incident light from a direction of a side surface of the nozzle tip to a first region of the imaging element, characterized in that the optical system includes a second optical system (88d, 88e, 88f) configured to guide incident light from a direction of the surface of the board to a second region of the imaging element in a state with the nozzle above the surface of the board, the imaging means is configured to be able to image an image of the side surface of the nozzle tip and an image of the surface of the board respectively via the first optical system (88a, 88b, 88c, 88e, 88f) and the second optical system (88d, 88e, 88f).