EasyJet said its average ticket prices were 31% higher between January and March compared with the same period last year.
But chief executive Johan Lundgren insisted the Luton-based airline “still provides great value” and demand is “stronger than ever”.
Passenger numbers reached 15.6 million during the first three months of 2023, up by more than a third from 11.6 million a year earlier.
Mr Lundgren told reporters that fares have risen due to “massive” cost increases, particularly for fuel.
He said it is “difficult to predict” how they will change this summer, and noted that the year-on-year rise between January and March represents a £12 increase per ticket in actual terms.
“We still provide great value for customers,” he insisted.
“Forty percent of all the fares that we have on sale right now actually sit below £50.
“It’s clear that we have a strong demand into the summer, but we want to make sure that we keep our fares attractive to our customers.”
EasyJet reported a loss before tax of £415 million for the six months to the end of March, compared with a £545 million loss in the same period in 2021/22.
It expects to outperform market expectations of a profit before tax of £260 million for the year to the end of September.
Mr Lundgren said people are prioritising holidays “even more than they did before”, and it is “the only thing that people say they will maintain their spend on or even increase”.
He added: “It’s driven on the fact that people are really focusing on experiences and doing things rather than investing in things that have to do with perhaps your home or any other things.”
Mr Lundgren also revealed that average trip durations have fallen to around seven days, down from as long as 12 days in the first year of the coronavirus pandemic.
“The travel pattern is coming back to normal and people will take more trips,” he said.