In the substrate-bottom receiving mechanism 20 of the lane A transporting conveyor 2A and lane B transporting conveyor 2B of the electronic component mounting device, on the rectangular-plate-shaped bottom receiving plate 23 that holds the bottom receiving pins 25 such that the bottom receiving position can be adjusted there is a rotating holding part 32 that rotates around pivotal shaft 31; the holding parts 30, which normally do not protrude over the upper surface and which protrude over the upper surface to be grasped only in the fetching operation by the operator, are arranged on the end surfaces on the upstream side and downstream side with respect to the substrate transporting direction of the bottom receiving plate 23, respectively; and the operator can hold the rotating holding part 32 to remove the bottom receiving plate 23.