Are disclosed a method of detecting a hold-position of an electronic component in which the component is held by an electronic-component holding apparatus, an electronic-component holding apparatus having a hold-position detecting device, and an electronic-component mounting apparatus for mounting an electronic component on a printed-circuit board. The above method includes the steps of emitting light beams in a direction toward the electronic component (W) held by the electronic-component holding apparatus (58, 70), so as to take a projection of the component, and of detecting a position of the projection, thereby detecting the hold-position of the component. The above holding apparatus is characterized in that at least a part of a holding head body (86) which surrounds a center line of a sucking pipe (88) is made of a transparent material, and in that the holding apparatus has the hold-position detecting device which includes a light emitter (146) for emitting light beams in a direction parallel to the center line of the sucking pipe so as to take a projection of the component held by the sucking pipe, and further includes an electronic image device (150) for detecting a position of the projection. The above mounting apparatus has at least one holding head (70) which is stopped at a pair of intervening stops between a receive-stop at which the head receives the component and a mount-stop at which the head mounts the component on the board, at one of the intervening stops the hold-position of the component being detected, at the other intervening stop an incorrect hold-position of the component being adjusted.