In an electronic part mounting apparatus having a rotary part supply unit for respectively mounting electronic part assemblies at predetermined positions of a substrate (14), said electronic part assemblies being mounted on a plurality of tape units (1) placed on a movable base (8), tape chips (4, 5), from which electronic parts (3) are removed, are guided via a chute (10) to the vicinity of rotating center of the base (8). The chips (4, 5) are then cut by a tape cutter (11) provided in the neighborhood of the chute (10) when the base (8) is rotated and stopped, thereby maintaining the selection of the parts (3) at random and preventing the bse from being disturbed by the smooth rotation of the base with the chips.