The Express convenience store, in Northampton, features five self-service tills that are supervised by one member of staff. There are no staffed checkouts.
Tesco said it was designed to speed up shopping trips. However, critics are concerned with the loss of basic human interaction during weekly shopping trips and the fact that it could lead to thousands of job losses.
The grocery giant insisted that the Express store in Kingsley was a trial and that it had no plans to open large supermarkets without checkout staff.
A Tesco spokesman said: "The number of staff won't change. The customer interaction won't change.
"We're creating over 11,000 jobs this year. We're creating jobs, not cutting them."
Sainsbury's and Asda have said that they have no plans to follow Tesco's lead and introduce self-service stores.