Abstract: There is disclosed an automatic electronic part-mounting apparatus in which acceleration, acting on electronic parts, suction-held respectively by mounting heads, is reduced, thereby enabling stable mounting of the electronic parts. Cam levers 10 are pivotally mounted through respective pivot shafts 9 on a rotary member 8 which is rotated at a constant speed by a roller gear cam 19. One end of the cam lever is engaged with a fixed cam 7 whereas the other end thereof is slidably mounted through cam followers on a follower lever 12 slidably mounted on annular rails 11 in a housing 6. One end of the follower lever 12 is slidably engaged with a cam follower, and the other end of the follower lever 12 is mounted on each mounting head 13. With this construction, the acceleration of the mounting head 13 can be reduced.