A data creation device configured to create allocation data indicating the installation order of holding tools, which is used in a mounting machine capable of installing any of multiple types of holding tools configured to hold leads of a lead component the data creation device comprising: a component data storage section configured to link in advance and store lead component shape data for multiple types of lead components and multiple types of holding tools capable of holding the leads of a lead component; a holding tool data storage section configured to store holding tool data including moving directions of the multiple holding tools and clamping directions for holding the lead components; a mounting data acquisition section configured to acquire mounting data, including the types and loading positions on the board, of each of previously-attached components and the lead components; a mounting order determination section configured to determine the mounting order of the lead components on the board based on the shape data and the mounting data of the lead components; a holding tool extraction section configured to extract a holding tool, for each lead component, capable of mounting components, according to the mounting order determined by the mounting order determination section, without interfering with previously-attached components based on the holding tool data; an installation order determination section configured to determine the installation order of holding tools capable of mounting all the lead components according to the mounting order determined by the mounting order determination section based on the holding tool extracted by the holding tool extraction section; and an allocation data creation section configured to create the allocation data according to the installation order determined by the installation order determination section. a component data storage section configured to link in advance and store lead component shape data for multiple types of lead components and multiple types of holding tools capable of holding the leads of a lead component; a holding tool data storage section configured to store holding tool data including moving directions of the multiple holding tools and clamping directions for holding the lead components; a mounting data acquisition section configured to acquire mounting data, including the types and loading positions on the board, of each of previously-attached components and the lead components; a mounting order determination section configured to determine the mounting order of the lead components on the board based on the shape data and the mounting data of the lead components; a holding tool extraction section configured to extract a holding tool, for each lead component, capable of mounting components, according to the mounting order determined by the mounting order determination section, without interfering with previously-attached components based on the holding tool data; an installation order determination section configured to determine the installation order of holding tools capable of mounting all the lead components according to the mounting order determined by the mounting order determination section based on the holding tool extracted by the holding tool extraction section; and an allocation data creation section configured to create the allocation data according to the installation order determined by the installation order determination section.