Two men were seen trying to fit a skimming device to a cash machine outside Barclays Bank in Station Road, Desborough, on Tuesday.
A spokesman for Northamptonshire Police said the incident was reported shortly after 1pm on Tuesday.
She added that the men had been seen trying to place something on the machine, but had been foiled because it was fitted with an anti-skimming device.
Damage was caused to the cash machine during the incident.
Anyone with information should contact Northamptonshire Police on 101.