noun
automatic ticket machine
Refers to a machine that sells tickets automatically, commonly found at train stations and event venues.
駅の自動券売機で切符を買った。
I bought a ticket at the station's automatic ticket machine.
券売機 is a shorter form meaning 'ticket vending machine', while 自動券売機 explicitly includes 'automatic'.
Compound of 自動 (automatic) + 券売機 (ticket vending machine).