A mounter comprising: a head unit that includes a suction nozzle capable of picking up an electronic component and is configured to transfer the electronic component to a specified position on a circuit board; an imaging device configured to image a pickup orientation of the electronic component picked up by the suction nozzle; a component data acquiring section configured to acquire a size of the electronic component; and an image processing section configured to process an image captured by the imaging device; characterized by further comprising: an image processing pattern selecting section configured to select an image processing range (60, 62), which is a portion of image data to be selectively image processed, and image processing accuracy of the image processing section, wherein the image processing pattern selecting section, based on the size of the electronic component, is able to select one image processing range (60, 62) from multiple predetermined image processing ranges (60, 62), is able to select one image processing accuracy from multiple predetermined image processing accuracies, and, as the size of the electronic component acquired from the component data acquiring section becomes smaller, is configured to select a smaller image processing range from the multiple image processing ranges (60, 62), and to select a more accurate image processing accuracy from the multiple image processing accuracies, and the image processing section is configured to perform image processing according to the image processing range (60, 62) and image processing accuracy selected by the image processing pattern selecting section. a head unit that includes a suction nozzle capable of picking up an electronic component and is configured to transfer the electronic component to a specified position on a circuit board; an imaging device configured to image a pickup orientation of the electronic component picked up by the suction nozzle; a component data acquiring section configured to acquire a size of the electronic component; and an image processing section configured to process an image captured by the imaging device; characterized by further comprising: an image processing pattern selecting section configured to select an image processing range (60, 62), which is a portion of image data to be selectively image processed, and image processing accuracy of the image processing section, wherein the image processing pattern selecting section, based on the size of the electronic component, is able to select one image processing range (60, 62) from multiple predetermined image processing ranges (60, 62), is able to select one image processing accuracy from multiple predetermined image processing accuracies, and, as the size of the electronic component acquired from the component data acquiring section becomes smaller, is configured to select a smaller image processing range from the multiple image processing ranges (60, 62), and to select a more accurate image processing accuracy from the multiple image processing accuracies, and the image processing section is configured to perform image processing according to the image processing range (60, 62) and image processing accuracy selected by the image processing pattern selecting section. an image processing pattern selecting section configured to select an image processing range (60, 62), which is a portion of image data to be selectively image processed, and image processing accuracy of the image processing section, wherein the image processing pattern selecting section, based on the size of the electronic component, is able to select one image processing range (60, 62) from multiple predetermined image processing ranges (60, 62), is able to select one image processing accuracy from multiple predetermined image processing accuracies, and, as the size of the electronic component acquired from the component data acquiring section becomes smaller, is configured to select a smaller image processing range from the multiple image processing ranges (60, 62), and to select a more accurate image processing accuracy from the multiple image processing accuracies, and the image processing section is configured to perform image processing according to the image processing range (60, 62) and image processing accuracy selected by the image processing pattern selecting section.