To resolve a problem in a lock mechanism wherein a method for connecting a vending machine body and a door by a chain is defective by being easily broken a portion for fixing the chain to the vending machine body or the door by using a tool and a method for attaching the chain to a side part of the automatic vending machine is a hindrance when installing a plurality of the automatic vending machines side by side.

This antitheft apparatus for the automatic vending machine is characterized by that it comprise two fixing parts 1 which can be coupled to the vending machine body and an opening and closing preventing part 2 preventing opening and closing of the door, the opening and closing preventing part has an arch shape having two end parts, and the two end parts of the opening and closing preventing part respectively form interlocking structures with the fixing parts.