It is intended to provide an electronic component mounting device and an operation performing method for mounting electronic components so that both the operation quality and the productivity can be improved. Height precision division information that divide the height precision required for up and down movements of operating heads into the first division which indicates a normal height precision and the second division which indicates that a high height precision is required based on the type of electronic components are stored as operation data beforehand. In operation performing procedures, when an electronic component belongs to the first division, an operating head is made to move up and down based on an approximate operation position height derived from an approximate curved surface of the top surface of a board which is calculated by using the height measurement result obtained by measuring a plurality of height measuring points on the surface of the board, and when the electronic component belongs to the second division, the operating head is made to move up and down based on an individual operation position height obtained by individually measuring the board height at the operation position.